Information Sending and Receiving Method and Related Device

ABSTRACT

Embodiments of this application disclose an information sending and receiving method and a related device. The method may include: sending, by a network device, first indication information to a terminal device, where the first indication information is carried by using m bits in a downlink signal, and the first indication information includes related information indicating a quantity n of synchronization signal blocks SS blocks included in a synchronization signal burst set SS burst set, where m&lt;log 2 N, N is a maximum value of a quantity of SS blocks supported in the SS burst set, both m and n are integers greater than 1, and n is less than or equal to N. According to the embodiments of this application, a prior-art problem that transmission overheads are relatively high when the network device indicates the quantity n of SS blocks to the terminal device can be resolved.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a continuation of International Application No.PCT/CN2o18/081805, filed on Apr. 4, 2018, which claims priority toChinese Patent Application No. 201710309704.0, filed on May 4, 2017. Thedisclosures of the aforementioned applications are hereby incorporatedby reference herein in their entireties.

TECHNICAL FIELD

The present invention relates to the field of network communications,and in particular, to an information sending and receiving method and arelated device.

BACKGROUND

In comparison with Long Term Evolution (LTE), a higher carrier frequencysuch as 38 GHz or 72 GHz is used in a 5G communications system, toimplement wireless communication with a larger bandwidth and a highertransmission rate. Because a carrier frequency is relatively high, aradio signal transmitted by using the carrier frequency encounters moresevere fading in a spatial propagation process, and even it is difficultto detect the radio signal at a receive end. Therefore, a beamformingtechnology is to be used in the 5G communications system to obtain abeam with good directivity, to increase power in a transmit directionand improve a signal to interference plus noise ratio (SINR) at thereceive end. To improve communication quality, the beamformingtechnology is also used on a user equipment (UE) side to generate analogbeams in different directions for receiving and sending data. Because abase station and user equipment communicate with each other by using arelatively narrow analog beam, better communication quality can beobtained only when the analog beams for sending and receiving arealigned. Therefore, it has been determined in the 3GPP RAN₁ meeting thata beam sweeping process is used in New Radio (NR) to determine a beampair between the base station and the UE, and a plurality of beam pairsare monitored in a communication process, to improve robustness of acommunication link.

Further, to extend coverage of a network device and ensure that aterminal device can quickly obtain a synchronization signal, systeminformation, and the like required for accessing a network, theinformation needs to periodically broadcast in NR. In NR, asynchronization signal block (SS block) includes a primarysynchronization signal (PSS), a secondary synchronization signal (SSS),and/or a new radio physical broadcast channel (NR-PBCH), and the SSblock may occupy a plurality of orthogonal frequency divisionmultiplexing (OFDM) symbols that are related to a carrier band and asubcarrier spacing. FIG. 1 is a schematic structural diagram of an SSburst set according to this application. One or more SS blocks form onesynchronization signal burst SS burst, and one or more SS bursts formone synchronization signal burst set SS burst set.

However, in an actual communication process, the network device may needto configure different quantities of SS blocks in an SS burst set basedon different service requirements. Therefore, how the network deviceeffectively notifies the terminal device of a quantity of SS blocks is aproblem that needs to be urgently resolved.

SUMMARY

To resolve a technical problem, embodiments of the present inventionprovide a method for indicating a quantity of synchronization signalblocks, a receiving method, and a related device, to resolve a problemthat transmission bit overheads are relatively high when a networkdevice in a 5G communications system notifies a terminal device of aquantity of SS blocks included in an SS burst set.

According to a first aspect, an embodiment of this application providesan information sending method, and the method may include:

sending, by a network device, first indication information to a terminaldevice, where the first indication information is carried by using mbits in a downlink signal, and the first indication information includesrelated information indicating a quantity n of synchronization signalblocks SS blocks included in a synchronization signal burst set SS burstset, where m<log₂N, N is a maximum value of a quantity of SS blockssupported in the SS burst set, both m and n are integers greater than 1,and n is less than or equal to N.

Optionally, the related information about n is an index corresponding toa value of n in a first quantity set, and the first quantity setincludes a plurality of values of the quantity of SS blocks supported inthe SS burst set.

Optionally, the SS burst set is corresponding to different firstquantity sets on different carrier bands, and that the first quantityset includes a plurality of values of the quantity of SS blockssupported in the SS burst set includes: the first quantity set includesa plurality of values of a quantity of SS blocks supported in the SSburst set on a current carrier band.

In this embodiment of this application, value sets corresponding to thequantity n of SS blocks on different carrier bands are separately agreedupon in advance. In addition, because some of possible values arespecified in a value set, and the other possible values are discarded,transmission overheads can be greatly reduced when index matching isperformed to indicate the quantity n of SS blocks.

Optionally, the SS burst set is corresponding to a same first quantityset on at least two carrier bands, and that the first quantity setincludes a plurality of values of the quantity of SS blocks supported inthe SS burst set includes: the first quantity set includes a pluralityof values of a quantity of SS blocks supported in the SS burst set oneach of the at least two carrier bands.

In this embodiment of this application, a value set corresponding to thequantity n of SS blocks on a plurality of carrier bands is agreed uponin advance. In addition, because some of possible values are specifiedin a value set, and the other possible values are discarded,transmission overheads can be greatly reduced when index matching isperformed to indicate the quantity n of SS blocks.

Optionally, the SS burst set is corresponding to different firstquantity sets in different SS burst set periods, and that the firstquantity set includes a plurality of values of the quantity of SS blockssupported in the SS burst set includes: the first quantity set includesa plurality of values of a quantity of SS blocks supported in the SSburst set in a current SS burst set period.

In this embodiment of this application, value sets corresponding to thequantity n of SS blocks in different SS burst set periods are separatelyagreed upon in advance. In addition, because some of possible values arespecified in a value set, and the other possible values are discarded,transmission overheads can be greatly reduced when index matching isperformed to indicate the quantity n of SS blocks.

Optionally, the SS burst set is corresponding to a same first quantityset in at least two SS burst set periods, and that the first quantityset includes a plurality of values of the quantity of SS blockssupported in the SS burst set includes: the first quantity set includesa plurality of values of a quantity of SS blocks supported in the SSburst set in each of the at least two SS burst set periods.

In this embodiment of this application, a value set corresponding to thequantity n of SS blocks in a plurality of SS burst set periods is agreedupon in advance. In addition, because some of possible values arespecified in a value set, and the other possible values are discarded,transmission overheads can be greatly reduced when index matching isperformed to indicate the quantity n of SS blocks.

Optionally, the method further includes: generating, by the networkdevice, demodulation reference signal DMRS sequences of a correspondingphysical broadcast channel PBCH based on different SS burst set periods;or generating, by the network device, corresponding pseudo noise PNsequences based on different SS burst set periods, and scrambling DMRSsby using the PN sequences.

Optionally, the SS burst set includes X synchronization signal bursts SSbursts, and each SS burst includes a same quantity of SS blocks; and therelated information about n is a quantity A of SS blocks in a single SSburst, where both X and A are integers greater than 1; or each SS burstin the SS burst set includes Y SS blocks; and the related informationabout n is a quantity B of SS bursts included in the SS burst set, whereboth Y and B are integers greater than 1.

In this embodiment of this application, because a quantity of SS burstsin an SS burst set is explicitly specified, and it is stipulated thateach SS burst includes a same quantity of SS blocks, only a specificquantity of SS blocks in each SS burst needs to be notified to theterminal device; or because a quantity of SS blocks in each SS burst isexplicitly specified, and it is stipulated that each SS burst includes asame quantity of SS blocks, only a specific quantity of SS bursts needsto be notified to the terminal device, so that transmission overheadscan be greatly reduced.

Optionally, the SS burst set includes X synchronization signal bursts SSbursts, and each SS burst includes a same quantity of SS blocks; and therelated information about n is an index corresponding to a value of aquantity A of SS blocks in a single SS burst in a second quantity set,and the second quantity set includes a plurality of values of thequantity A of SS blocks in the single SS burst, where both X and A areintegers greater than 1; or each SS burst in the SS burst set includes YSS blocks; and the related information about n is an index correspondingto a value of a quantity B of SS bursts included in the SS burst set ina third quantity set, and the third quantity set includes a plurality ofvalues of the quantity B of SS bursts included in the SS burst set,where both Y and B are integers greater than 1.

In this embodiment of this application, only an index of a specificquantity of SS blocks in each SS burst needs to be indicated or only anindex of a specific quantity of SS bursts needs to be indicated, so thattransmission overheads are further reduced.

Optionally, the downlink signal includes a first system message andfirst dedicated signaling; and that the first indication information iscarried by using m bits in a downlink signal includes: the firstindication information is carried by using Q bits in the first systemmessage and m−Q bits in the first dedicated signaling together, where Qis an integer greater than o, and Q is less than m.

This embodiment of this application provides a specific implementationin which the network device enables the m bits in the downlink signal tocarry the first indication information.

Optionally, the first system message is a message carried on thephysical broadcast channel PBCH or remaining minimum system informationRMSI; and/or the first dedicated signaling is any one of radio resourcecontrol RRC signaling, Media Access Control baseband resource MAC CEsignaling, downlink control information DCI signaling, and presetdedicated signaling that is used to carry the related information aboutn.

This embodiment of this application provides a specific implementationin which the network device enables the m bits in the downlink signal tocarry the first indication information.

Optionally, the downlink signal includes a second system message, thesecond system message includes a plurality of types of messages, and theplurality of types of messages include at least a message carried on thephysical broadcast channel PBCH and remaining minimum systeminformation; and that the first indication information is carried byusing m bits in a downlink signal includes: the first indicationinformation is carried by using m bits in at least one of the pluralityof types of messages.

This embodiment of this application provides a specific implementationin which the network device enables the m bits in the downlink signal tocarry the first indication information.

Optionally, the related information about n is group indexes andintra-group indexes that are of groups to which the quantity n of SSblocks belongs, and the groups are I groups obtained after H values ofthe quantity of SS blocks supported in the SS burst set are classified,where both H and I are integers greater than 1, and I is less than H;and that the first indication information is carried by using m bits ina downlink system signal includes: the group indexes are carried byusing Q bits in the first system message and the intra-group indexes arecarried by using m−Q bits in the first dedicated signaling, where Q isan integer greater than o.

In this embodiment of this application, a plurality of values of thequantity n of SS blocks are agreed upon in advance, the plurality ofvalues are classified, and then the quantity n of SS blocks is indicatedby matching a corresponding index. In this way, not only transmissionoverheads can be reduced, but also efficiency of identifying thequantity n of SS blocks by the terminal device can be improved.

According to a second aspect, an embodiment of this application providesan information receiving method, and the method may include:

receiving, by a terminal device, first indication information sent by anetwork device, where the first indication information is carried byusing m bits in a downlink signal, and the first indication informationincludes related information indicating a quantity n of synchronizationsignal blocks SS blocks included in a synchronization signal burst setSS burst set, where m<log₂N, and N is a maximum value of a quantity ofSS blocks supported in the SS burst set; and determining, by theterminal device, the quantity n of SS blocks according to the firstindication information.

Optionally, the related information about n is an index corresponding toa value of n in a first quantity set, and the first quantity setincludes a plurality of values of the quantity of SS blocks supported inthe SS burst set; and the determining, by the terminal device, thequantity n of SS blocks according to the first indication informationincludes: determining, by the terminal device, the quantity n of SSblocks based on the first quantity set and the corresponding index.

Optionally, the SS burst set is corresponding to different firstquantity sets on different carrier bands; and before the determining, bythe terminal device, the quantity n of SS blocks according to the firstindication information, the method further includes: determining, by theterminal device, a current carrier band of the SS burst set; anddetermining, by the terminal device, a corresponding first quantity setbased on the determined carrier band.

Optionally, the SS burst set is corresponding to different firstquantity sets in different SS burst set periods; and before thedetermining, by the terminal device, the quantity n of SS blocksaccording to the first indication information, the method furtherincludes: determining, by the terminal device, a current SS burst setperiod of the SS burst set; and determining, by the terminal device, acorresponding first quantity set based on the determined SS burst setperiod.

Optionally, demodulation reference signal DMRS sequences that are of acorresponding physical broadcast channel PBCH and that are generated indifferent SS burst set periods are different; or DMRS sequences that arescrambled by using corresponding pseudo noise PN sequences and that aregenerated in different SS burst set periods are different; and thedetermining, by the terminal device, a current SS burst set period ofthe SS burst set includes: determining, by the terminal device, thecurrent SS burst set period of the SS burst set based on the DMRSsequence or the DMRS sequence scrambled by using the PN sequence.

According to a third aspect, an embodiment of this application providesan information sending method, and the method may include:

sending, by a network device, second indication information to aterminal device, where the second indication information is carried byusing a bits in a downlink system message and b bits associated with adownlink reference signal, and the second indication information is usedto indicate a quantity n of synchronization signal blocks SS blocksincluded in a synchronization signal burst set SS burst set, wherea+b=log₂N, N is a maximum value of a quantity of SS blocks supported inthe SS burst set, a, b, and n all are integers greater than o, and n isless than or equal to N.

In this embodiment of this application, the second indicationinformation is distributed in the downlink system message and thedownlink reference signal for joint transmission, thereby reducingoverheads of one of the message or the signal.

Optionally, the downlink system message is a message carried on aphysical broadcast channel PBCH, and the downlink reference signal is ademodulation reference signal DMRS sequence of the PBCH; and that thesecond indication information is carried by using a bits in a downlinksystem message and b bits associated with a downlink reference signalincludes: the second indication information is carried by using a bitsin the message carried on the PBCH and b bits associated with the DMRSsequence, where the b bits associated with the DMRS sequence include bitinformation used to generate the DMRS sequence or bit information usedto generate a PN sequence for scrambling the DMRS sequence.

According to a fourth aspect, an embodiment of this application providesan information receiving method, and the method may include:

receiving, by a terminal device, second indication information sent by anetwork device, where the second indication information is carried byusing a bits in a downlink system message and b bits associated with adownlink reference signal, and the second indication information is usedto indicate a quantity n of synchronization signal blocks SS blocksincluded in a synchronization signal burst set SS burst set, wherea+b=log₂N, N is a maximum value of a quantity of SS blocks supported inthe SS burst set, a, b, and n all are integers greater than o, and n isless than or equal to N; and

determining, by the terminal device, the quantity n of SS blocksaccording to the second indication information.

Optionally, the downlink system message is a message carried on aphysical broadcast channel PBCH, and the downlink reference signal is ademodulation reference signal DMRS sequence of the PBCH; and that thesecond indication information is carried by using a bits in a downlinksystem message and b bits associated with a downlink reference signalincludes: the second indication information is carried by using a bitsin the message carried on the PBCH and b bits associated with the DMRSsequence, where the b bits associated with the DMRS sequence include bitinformation used to generate the DMRS sequence or bit information usedto generate a PN sequence for scrambling the DMRS sequence.

According to a fifth aspect, an embodiment of this application providesa network device, and the network device may include:

a communications unit, configured to send first indication informationto a terminal device, where the first indication information is carriedby using m bits in a downlink signal, and the first indicationinformation includes related information indicating a quantity n ofsynchronization signal blocks SS blocks included in a synchronizationsignal burst set SS burst set, where m<log₂N, N is a maximum value of aquantity of SS blocks supported in the SS burst set, both m and n areintegers greater than 1, and n is less than or equal to N.

Optionally, the related information about n is an index corresponding toa value of n in a first quantity set, and the first quantity setincludes a plurality of values of the quantity of SS blocks supported inthe SS burst set.

Optionally, the SS burst set is corresponding to different firstquantity sets on different carrier bands, and that the first quantityset includes a plurality of values of the quantity of SS blockssupported in the SS burst set includes:

the first quantity set includes a plurality of values of a quantity ofSS blocks supported in the SS burst set on a current carrier band.

Optionally, the SS burst set is corresponding to a same first quantityset on at least two carrier bands, and that the first quantity setincludes a plurality of values of the quantity of SS blocks supported inthe SS burst set includes:

the first quantity set includes a plurality of values of a quantity ofSS blocks supported in the SS burst set on each of the at least twocarrier bands.

Optionally, the SS burst set is corresponding to different firstquantity sets in different SS burst set periods, and that the firstquantity set includes a plurality of values of the quantity of SS blockssupported in the SS burst set includes:

the first quantity set includes a plurality of values of a quantity ofSS blocks supported in the SS burst set in a current SS burst setperiod.

Optionally, the SS burst set is corresponding to a same first quantityset in at least two SS burst set periods, and that the first quantityset includes a plurality of values of the quantity of SS blockssupported in the SS burst set includes:

the first quantity set includes a plurality of values of a quantity ofSS blocks supported in the SS burst set in each of the at least two SSburst set periods.

Optionally, the network device further includes:

a processing unit, configured to: generate demodulation reference signalDMRS sequences of a corresponding physical broadcast channel PBCH basedon different SS burst set periods; or generate corresponding pseudonoise PN sequences based on different SS burst set periods, and scrambleDMRSs by using the PN sequences.

Optionally, the SS burst set includes X synchronization signal bursts SSbursts, and each SS burst includes a same quantity of SS blocks; and therelated information about n is a quantity A of SS blocks in a single SSburst, where both X and A are integers greater than 1; or each SS burstin the SS burst set includes Y SS blocks; and the related informationabout n is a quantity B of SS bursts included in the SS burst set, whereboth Y and B are integers greater than 1.

Optionally, the SS burst set includes X synchronization signal bursts SSbursts, and each SS burst includes a same quantity of SS blocks; and therelated information about n is an index corresponding to a value of aquantity A of SS blocks in a single SS burst in a second quantity set,and the second quantity set includes a plurality of values of thequantity A of SS blocks in the single SS burst, where both X and A areintegers greater than 1; or each SS burst in the SS burst set includes YSS blocks; and the related information about n is an index correspondingto a value of a quantity B of SS bursts included in the SS burst set ina third quantity set, and the third quantity set includes a plurality ofvalues of the quantity B of SS bursts included in the SS burst set,where both Y and B are integers greater than 1.

Optionally, the downlink signal includes a first system message andfirst dedicated signaling; and that the first indication information iscarried by using m bits in a downlink signal includes: the firstindication information is carried by using Q bits in the first systemmessage and m−Q bits in the first dedicated signaling together, where Qis an integer greater than o, and Q is less than m.

Optionally, the first system message is a message carried on thephysical broadcast channel PBCH or remaining minimum system informationRMSI; and/or the first dedicated signaling is any one of radio resourcecontrol RRC signaling, Media Access Control baseband resource MAC CEsignaling, downlink control information DCI signaling, and presetdedicated signaling that is used to carry the related information aboutn.

Optionally, the downlink signal includes a second system message, thesecond system message includes a plurality of types of messages, and theplurality of types of messages include at least a message carried on thephysical broadcast channel PBCH and remaining minimum systeminformation; and that the first indication information is carried byusing m bits in a downlink signal includes: the first indicationinformation is carried by using m bits in at least one of the pluralityof types of messages.

Optionally, the related information about n is group indexes andintra-group indexes that are of groups to which the quantity n of SSblocks belongs, and the groups are I groups obtained after H values ofthe quantity of SS blocks supported in the SS burst set are classified,where both H and I are integers greater than 1, and I is less than H;and that the first indication information is carried by using m bits ina downlink system signal includes: the group indexes are carried byusing Q bits in the first system message and the intra-group indexes arecarried by using m−Q bits in the first dedicated signaling, where Q isan integer greater than o.

According to a sixth aspect, an embodiment of this application providesa terminal device, and the terminal device may include:

a communications unit, configured to receive first indicationinformation sent by a network device, where the first indicationinformation is carried by using m bits in a downlink signal, and thefirst indication information includes related information indicating aquantity n of synchronization signal blocks SS blocks included in asynchronization signal burst set SS burst set, where m<log₂N, and N is amaximum value of a quantity of SS blocks supported in the SS burst set;and

a processing unit, configured to determine the quantity n of SS blocksaccording to the first indication information.

Optionally, the related information about n is an index corresponding toa value of n in a first quantity set, and the first quantity setincludes a plurality of values of the quantity of SS blocks supported inthe SS burst set.

That the processing unit is configured to determine the quantity n of SSblocks according to the first indication information is specifically:

determining the quantity n of SS blocks based on the first quantity setand the corresponding index.

Optionally, the SS burst set is corresponding to different firstquantity sets on different carrier bands, and the processing unit isfurther configured to:

before determining the quantity n of SS blocks according to the firstindication information, determine a current carrier band of the SS burstset, and determine a corresponding first quantity set based on thedetermined carrier band.

Optionally, the SS burst set is corresponding to different firstquantity sets in different SS burst set periods, and the processing unitis further configured to:

before determining the quantity n of SS blocks according to the firstindication information, determine a current SS burst set period of theSS burst set, and determine a corresponding first quantity set based onthe determined SS burst set period.

Optionally, demodulation reference signal DMRS sequences that are of acorresponding physical broadcast channel PBCH and that are generated indifferent SS burst set periods are different; or DMRS sequences that arescrambled by using corresponding pseudo noise PN sequences and that aregenerated in different SS burst set periods are different. That theprocessing unit is configured to determine a current SS burst set periodof the SS burst set is specifically: determining the current SS burstset period of the SS burst set based on the DMRS sequence or the DMRSsequence scrambled by using the PN sequence.

According to a seventh aspect, an embodiment of this applicationprovides a network device, and the network device may include:

a communications unit, configured to send second indication informationto a terminal device, where the second indication information is carriedby using a bits in a downlink system message and b bits associated witha downlink reference signal, and the second indication information isused to indicate a quantity n of synchronization signal blocks SS blocksincluded in a synchronization signal burst set SS burst set, wherea+b=log₂N, N is a maximum value of a quantity of SS blocks supported inthe SS burst set, a, b, and n all are integers greater than 0, and n isless than or equal to N.

Optionally, the downlink system message is a message carried on aphysical broadcast channel PBCH, and the downlink reference signal is ademodulation reference signal DMRS sequence of the PBCH; and that thesecond indication information is carried by using a bits in a downlinksystem message and b bits associated with a downlink reference signalincludes: the second indication information is carried by using a bitsin the message carried on the PBCH and b bits associated with the DMRSsequence, where the b bits associated with the DMRS sequence include bitinformation used to generate the DMRS sequence or bit information usedto generate a PN sequence for scrambling the DMRS sequence.

According to an eighth aspect, an embodiment of this applicationprovides a network device, and the network device may include:

a communications unit, configured to receive second indicationinformation sent by a network device, where the second indicationinformation is carried by using a bits in a downlink system message andb bits associated with a downlink reference signal, and the secondindication information is used to indicate a quantity n ofsynchronization signal blocks SS blocks included in a synchronizationsignal burst set SS burst set, where a+b=log₂N, N is a maximum value ofa quantity of SS blocks supported in the SS burst set, a, b, and n allare integers greater than 0, and n is less than or equal to N; and aprocessing unit, configured to determine, by the terminal device, thequantity n of SS blocks according to the second indication information.

Optionally, the downlink system message is a message carried on aphysical broadcast channel PBCH, and the downlink reference signal is ademodulation reference signal DMRS sequence of the PBCH; and that thesecond indication information is carried by using a bits in a downlinksystem message and b bits associated with a downlink reference signalincludes: the second indication information is carried by using a bitsin the message carried on the PBCH and b bits associated with the DMRSsequence, where the b bits associated with the DMRS sequence include bitinformation used to generate the DMRS sequence or bit information usedto generate a PN sequence for scrambling the DMRS sequence.

According to a ninth aspect, this application provides a network device,and the network device has a function of implementing the method in anyone of the foregoing information sending method embodiments. Thefunction may be implemented by hardware or may be implemented byhardware executing corresponding software. The hardware or the softwareincludes one or more modules corresponding to the foregoing function.

According to a tenth aspect, this application provides a terminaldevice, and the terminal device has a function of implementing themethod in any one of the foregoing information receiving methodembodiments. The function may be implemented by hardware or may beimplemented by hardware executing corresponding software. The hardwareor the software includes one or more modules corresponding to theforegoing function.

According to an eleventh aspect, this application provides a networkdevice. The network device includes a processor, and the processor isconfigured to support the network device in performing a correspondingfunction in the information sending method provided in the first aspector the third aspect. The network device may further include a memory.The memory is coupled to the processor, and stores a program instructionand data that are necessary for the network device. The network devicemay further include a communications interface, configured to implementcommunication between the network device and another device or acommunications network.

According to a twelfth aspect, this application provides a terminaldevice. The terminal device includes a processor, and the processor isconfigured to support the terminal device in performing a correspondingfunction in the control information receiving method provided in thesecond aspect or the fourth aspect. The terminal device may furtherinclude a memory. The memory is coupled to the processor, and stores aprogram instruction and data that are necessary for the terminal device.The terminal device may further include a communications interface,configured to implement communication between the terminal device andanother device or a communications network.

According to a thirteenth aspect, this application provides a computerstorage medium, configured to store a computer software instruction usedby the network device provided in the eleventh aspect, where thecomputer software instruction includes a program designed to perform theforegoing aspect.

According to a fourteenth aspect, this application provides a computerstorage medium, configured to store a computer software instruction usedby the terminal device provided in the twelfth aspect, where thecomputer software instruction includes a program designed to perform theforegoing aspect.

According to a fifteenth aspect, an embodiment of this applicationprovides a computer program, and the computer program includes aninstruction. When the computer program is executed by a computer, thecomputer can perform the procedure of the information sending method ineither the first aspect or the third aspect.

According to a sixteenth aspect, an embodiment of this applicationprovides a computer program, and the computer program includes aninstruction. When the computer program is executed by a computer, thecomputer can perform the procedure of the information receiving methodin either the second aspect or the fourth aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

To describe the technical solutions in the embodiments of thisapplication or in the background more clearly, the following describesthe accompanying drawings required for describing the embodiments ofthis application or the background.

FIG. 1 is a schematic structural diagram of an SS burst set according tothis application;

FIG. 2 is a diagram of a communications network architecture accordingto an embodiment of this application;

FIG. 3 is a schematic flowchart of an information sending and receivingmethod according to an embodiment of this application;

FIG. 4 is a schematic flowchart of another information sending andreceiving method according to an embodiment of this application;

FIG. 5 is a schematic structural diagram of a network device accordingto an embodiment of this application;

FIG. 6 is a schematic structural diagram of a terminal device accordingto an embodiment of this application;

FIG. 7 is a schematic structural diagram of another network deviceaccording to an embodiment of this application;

FIG. 8 is a schematic structural diagram of another terminal deviceaccording to an embodiment of this application; and

FIG. 9 is a schematic structural diagram of a device according to anembodiment of this application.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The following describes the embodiments of this application withreference to the accompanying drawings in the embodiments of thisapplication.

In the specification, the claims, and the accompanying drawings of thisapplication, the terms “first”, “second”, “third”, “fourth”, and thelike are intended to distinguish between different objects but do notindicate a particular order. In addition, the terms “including” and“having” and any other variant thereof are intended to cover anon-exclusive inclusion. For example, a process, a method, a system, aproduct, or a device that includes a series of steps or units is notlimited to the listed steps or units, but optionally further includes anunlisted step or unit, or optionally further includes another inherentstep or unit of the process, the method, the product, or the device.

“Embodiment” mentioned in this specification means that a particularcharacteristic, structure, or feature described with reference to theembodiments may be included in at least one embodiment of thisapplication. The phrase in various locations in this specification doesnot necessarily refer to a same embodiment, and is not an independent oralternate embodiment exclusive of another embodiment. Persons skilled inthe art understand, in explicit and implicit manners, that an embodimentdescribed in this specification may be combined with another embodiment.

The terms such as “component”, “module”, and “system” used in thisspecification are used to indicate computer-related entities, hardware,firmware, combinations of hardware and software, software, or softwarebeing executed. For example, a component may be but is not limited to aprocess that runs on a processor, a processor, an object, an executablefile, a thread of execution, a program, and/or a computer. As shown infigures, both a computing device and an application that runs on acomputing device may be components. One or more components may residewithin a process and/or a thread of execution, and components may belocated on one computer and/or distributed between two or morecomputers. In addition, these components may be executed from variouscomputer readable media that store various data structures. For example,the components may communicate by using a local and/or remote processand according to, for example, a signal having one or more data packets(for example, data from two components interacting with anothercomponent in a local system, a distributed system, and/or across anetwork such as the Internet interacting with other systems by using thesignal).

It should be understood that the embodiments of the present inventionmay be applied to a next-generation communications system such as a 5Gradio access (NR) system, which is referred to as a 5GNR system forshort.

Usually, a conventional communications system supports a limitedquantity of connections, and is easy to implement. However, withevolution of a communications technology, in addition to conventionalcommunication, a mobile communications system supports, for example,device-to-device (D2D) communication, machine-to-machine (M2M)communication, machine type communication (MTC), and vehicle to vehicle(V2V) communication.

The embodiments are described with respect to a sending device and areceiving device in the embodiments of the present invention.

A terminal device may also be referred to as user equipment (UE), anaccess terminal, a subscriber unit, a subscriber station, a mobilestation, a mobile console, a remote station, a remote terminal, a mobiledevice, a user terminal, a terminal, a wireless communications device, auser agent, or a user apparatus. The terminal device may be a station(STA) in a wireless local area network (WLAN), or may be a cellularphone, a cordless phone, a Session Initiation Protocol (SIP) phone, awireless local loop (WLL) station, a personal digital assistant (PDA)device, a handheld device or a computing device having a wirelesscommunication function, another processing device connected to awireless modem, an in-vehicle device, a wearable device, a terminaldevice in a next-generation communications system such as a 5thGeneration (5G) network, a terminal device in a future evolved publicland mobile network (PLMN), or the like.

As an example instead of a limitation, in the embodiments of the presentinvention, the terminal device may be alternatively a wearable device.The wearable device may also be referred to as a wearable intelligentdevice, and is a general term of wearable devices, such as glasses,gloves, watches, clothes, and shoes, that are developed by applying awearable technology to intelligent designs of daily wearing. Thewearable device is a portable device that can be directly worn on a bodyor integrated into clothes or an accessory of a user. The wearabledevice is not merely a hardware device, but is used to implement apowerful function through software support, data interaction, and cloudinteraction. Generalized wearable intelligent devices includefull-featured and large-size devices that can implement complete orpartial functions without depending on smartphones, such as smartwatches or smart glasses, and devices that focus on only one type ofapplication function and need to work with other devices such assmartphones, for example, various smart bracelets or smart jewelry forvital sign monitoring.

In addition, the embodiments are described with respect to a networkdevice in the embodiments of the present invention. The network devicemay be a device for communicating with a mobile device or the like. Thenetwork device may be an access point (AP) in a WLAN, a relay station oran access point, an in-vehicle device, a wearable device, a networkdevice (g Node B (gNB or gNodeB)) in a future 5G network, a networkdevice in a future evolved PLMN network, or the like.

In addition, in the embodiments of the present invention, the networkdevice provides a service for a cell. The terminal device communicateswith the network device by using a transmission resource (for example, afrequency domain resource or a spectrum resource) used in the cell. Thecell may be a cell corresponding to the network device (for example, abase station). The cell may belong to a macro base station, or a basestation corresponding to a small cell. The small cell herein may includea metro cell, a micro cell, a pico cell, a femto cell, or the like. Thesmall cells have features such as small coverage and low transmit power,and are adapted to provide high-rate data transmission services.

In addition, a plurality of cells may work in a same frequency on acarrier in a 5G system. In some special scenarios, it may be consideredthat the carrier and the cell are equivalent in concept. For example, ina carrier aggregation (CA) scenario, when a secondary component carrieris configured for the terminal device, both a carrier index of thesecondary component carrier and a cell identifier (cell ID) of asecondary serving cell that works on the secondary component carrier arecarried. In this case, it may be considered that the carrier and thecell are equivalent in concept. For example, access to a carrier by theterminal device is equivalent to access to a cell by the terminaldevice.

The method and the related device provided in the embodiments of thepresent invention may be applied to a terminal device or a networkdevice. The terminal device or the network device includes a hardwarelayer, an operating system layer running above the hardware layer, andan application layer running above the operating system layer. Thehardware layer includes hardware such as a central processing unit(CPU), a memory management unit (MMU), and a memory (which is alsoreferred to as a main memory). The operating system may be any one ormore computer operating systems that implement service processing byusing a process, such as the Linux operating system, the UNIX operatingsystem, the Android operating system, the iOS operating system, or theWindows operating system. The application layer includes applicationssuch as a browser, a contact list, word processing software, and instantcommunication software. In addition, in the embodiments of the presentinvention, a specific structure of an entity for performing a controlinformation transmission method is not specially limited in theembodiments of the present invention, provided that the entity can run aprogram recording code of the control information transmission method inthe embodiments of the present invention, to perform communication basedon the control information transmission method in the embodiments of thepresent invention. For example, a wireless communication method in theembodiments of the present invention may be performed by a terminaldevice or a network device, or a functional module that is in a terminaldevice or a network device and that can invoke a program and execute theprogram.

In addition, each aspect or feature of the embodiments of the presentinvention may be implemented as a method, an apparatus, or a productthat uses standard programming and/or engineering technologies. The term“product” used in this application covers a computer program that can beaccessed from any computer readable component, carrier, or medium. Forexample, computer readable medium may include but is not limited to: amagnetic storage device (for example, a hard disk, a floppy disk, or amagnetic tape), an optical disc (for example, a compact disc (CD) or adigital versatile disc (DVD)), a smart card, and a flash memory device(for example, an erasable programmable read only memory (EPROM), a card,a stick, or a key drive). In addition, various storage media describedin this specification may indicate one or more devices and/or othermachine readable media that are used to store information. The term“machine readable media” may include but is not limited to a radiochannel, and various other media that can store, contain, and/or carryan instruction and/or data.

First, a to-be-resolved technical problem and an application scenario inthis application are proposed. In an actual communication process, anetwork device may need to configure different quantities of SS blocksin an SS burst set based on different service requirements. Therefore,to improve efficiency of communication between the network device and aterminal device, the network device usually needs to notify the terminaldevice of a quantity of SS blocks in real time.

Currently, in the 3GPP RAN₁ # 88bis meeting, an agreement that aquantity of actually used SS blocks is sent by using a physicalbroadcast channel (PBCH), remaining minimum system information (RMSI),other system information (other SI), dedicated signaling (dedicatedsignaling), and the like is reached. However, no public document hasdisclosed related technical details. It may be considered that in anexisting solution, the quantity of SS blocks is directly transmitted inone of the foregoing manners.

In addition, currently, NR has agreed that a maximum of 64 SS blocks aresupported in one SS burst set on a band higher than 6 GHz but lower than52.6 GHz, and a maximum of eight SS blocks are supported on a band lowerthan 6 GHz. Obviously, a maximum quantity of supported SS blocks on thehigh band is different from that on the low band, and thereforequantities of bits for representing the information on the high band andthe low band are also different, which are respectively 6 bits and 3bits. Therefore, the prior art has the following problem: If 6 bits aredirectly placed on a PBCH for the high band, system overheads aregreatly increased. If different quantities of bits are used to representquantities of SS blocks on the high band and the low band and the bitsare placed on a PBCH, a size of the PBCH varies on the high band and thelow band, and different rate matching needs to be performed.

However, because a quantity of SS blocks is usually relatively large andneeds to change based on a service requirement, relatively hightransmission bit overheads may be generated, and communicationefficiency is reduced. Therefore, a technical problem to be resolved inthis application is how to enable the network device to notify, by usingrelatively low overheads in an effective information notificationmethod, the terminal device of a quantity n of SS blocks included in anSS burst set.

Based on the above, to facilitate understanding of the embodiments ofthis application, the following first describes a communications systemarchitecture on which the embodiments of this application are based.

FIG. 2 is a diagram of a communications system architecture according toan embodiment of this application. The communications systemarchitecture includes a core network, a network device, and a terminaldevice. As an example instead of a limitation, the core network providesa related service for an entire communication process, the networkdevice indicates a quantity of SS blocks to an accessed terminal device,and the terminal device performs SS block sweeping by using the quantityof SS blocks that is indicated by the network device.

The terminal device may be a user-side device in the communicationssystem. The terminal device can use a beamforming technology to generateanalog beams in different directions for receiving and sending data, andcan determine a beam pair between the terminal device and the networkdevice by using a beam sweeping process.

The network device may be a network-side network element in a 5Gcommunications system, for example, a gNB in the 5G communicationssystem. Specifically, the network device can determine a beam pairbetween the network device and the terminal device by using a beamsweeping process, and monitors a plurality of beam pairs in acommunication process, to improve robustness of a communication link. Toextend coverage of the network device and ensure that the terminaldevice can quickly obtain a synchronization signal, system information,and the like required for accessing a network, the network device canfurther periodically broadcast the information. It may be understoodthat the network device and the terminal device communicate with eachother by using a relatively narrow analog beam, better communicationquality can be obtained only when the analog beams for sending andreceiving are aligned. For more details, refer to descriptions in thefollowing embodiments.

It may be understood that the communications system architecture in FIG.2 is merely an example implementation in the embodiments of thisapplication. A communications system architecture in the embodiments ofthis application includes but is not limited to the foregoingcommunications system architecture.

With reference to the information receiving and sending methodembodiment provided in this application, the following specificallyanalyzes and resolves the technical problem proposed in thisapplication.

FIG. 3 is a schematic flowchart of an information sending and receivingmethod according to an embodiment of this application. The method may beapplied to the communications system in FIG. 2. The following describesthe method from a perspective of interaction between a network deviceand a terminal device with reference to FIG. 3, and the method mayinclude the following steps S301 to S303.

Step S01. A network device sends first indication information to aterminal device.

Specifically, the first indication information is carried by using mbits in a downlink signal, and the first indication information includesrelated information indicating a quantity n of synchronization signalblocks SS blocks included in a synchronization signal burst set SS burstset, where m<log₂N, N is a maximum value of a quantity of SS blockssupported in the SS burst set, both m and n are integers greater than 1,and n is less than or equal to N.

If the quantity n of SS blocks included in the SS burst set is directlysent on the downlink signal, log₂N bits need to be occupied, andconsequently transmission overheads are relatively high. In addition,when the quantity n of SS blocks included in the SS burst set isrelatively small, the quantity n still needs to be transmitted by usingthe log₂N bits corresponding to a case in which n is the maximum valueN, and consequently more resources are inevitably wasted. In thisapplication, the network device does not directly send, to the terminaldevice, the quantity n of SS blocks included in the SS burst set, butsends the related information about the quantity n such as indexinformation or information simplified according to a protocolstipulation, so that transmission overheads can be reduced.

Step S302: The terminal device receives the first indication informationsent by the network device.

Specifically, the first indication information is carried by using the mbits in the downlink signal, and the first indication informationincludes the related information indicating the quantity n ofsynchronization signal blocks SS blocks included in the synchronizationsignal burst set SS burst set, where m<log₂N, and N is the maximum valueof the quantity of SS blocks supported in the SS burst set.

The terminal device receives the first indication information on thecorresponding downlink signal according to the protocol stipulation,that is, receives and obtains the related information indicating thequantity n of SS blocks included in the SS burst set.

Step S303: The terminal device determines the quantity n of SS blocksaccording to the first indication information.

Specifically, the terminal device calculates or determines the quantityn of actually included SS blocks according to the first indicationinformation and the protocol stipulation and based on the relatedinformation that is about the quantity n of SS blocks included in the SSburst set and that is included in the first indication information, toperform sweeping based on the quantity n.

Based on a general idea of the foregoing embodiment corresponding toFIG. 3, the following specifically describes, with reference to exampleimplementations, how the network device sends the first indicationinformation to the terminal device, and how the network deviceindicates, to the terminal device by using the related information aboutn, the quantity of SS blocks included in the SS burst set, therebyreducing transmission overheads.

First, specific implementations are classified into two types becausethe related information about n included in the first indicationinformation varies.

Type 1: The related information about n is an index corresponding to avalue of n in a first quantity set, and the first quantity set includesa plurality of values of the quantity of SS blocks supported in the SSburst set. In other words, the related information about n mainlyincludes an index corresponding to a specific value of n. This type ofimplementation may specifically include the following Manner 1 to Manner4:

Manner 1:

In Manner 1, the SS burst set is corresponding to different firstquantity sets on different carrier bands, and the first quantity setincludes a plurality of values of a quantity of SS blocks supported inthe SS burst set on a current carrier band. That is, a protocolpre-stipulates sets of quantities n of SS blocks separately supported inthe SS burst set on different carrier bands, and stipulates indexesseparately corresponding to elements (values of n) in the sets. Then, anindex corresponding to a value of n is sent to the terminal device byusing the m bits in the downlink signal (for example, separately orjointly using a system message and signaling). A specific implementationmay be as follows:

1. The protocol stipulates maximum quantities of supported SS blocks ondifferent carrier bands. For example, when a carrier band is lower than6 GHz, a maximum value of a quantity of supported SS blocks is N=8; whena carrier band is higher than 6 GHz but lower than 52.6 GHz, a maximumvalue of a quantity of supported SS blocks is N=64. In this case,log₂N=3 for the carrier band lower than 6 GHz, and log₂N=6 for thecarrier band higher than 6 GHz but lower than 52.6 GHz.

2. The protocol stipulates that different carrier bands arecorresponding to different first quantity sets, and the first quantityset includes a plurality of values of a quantity of SS blocks supportedin the SS burst set on a current corresponding carrier band. Forexample, if a carrier band is lower than 6 GHz, a corresponding firstquantity set is {1, 2, 4, 8}, and it indicates that only 1, 2, 4, or 8SS blocks can be supported in the SS burst set on the low carrier band;if a carrier band is higher than 6 GHz but lower than 52.6 GHz, acorresponding first quantity set is {8, 16, 32, 64}, and it indicatesthat only 8, 16, 32, or 64 SS blocks can be supported in the SS burstset on the high carrier band. It may be understood that in thisimplementation, a value of m is related to a quantity of values of aquantity n of supported SS blocks on a carrier band, that is, a quantityof elements in a first quantity set corresponding to a low carrier bandmay be the same as or may be different from a quantity of elements in afirst quantity set corresponding to a high carrier band. If the twoquantities are the same, m is equal on different carrier bands, and inthis case, the network device sends the first indication information byusing a same information format on different carrier bands. If the twoquantities are different, m is not equal on different carrier bands, andin this case, the network device sends the first indication informationby using different information formats. It may be understood that theterminal device also correspondingly receives and parses the firstindication information by using a same information format or differentinformation formats.

3. The protocol further stipulates indexes corresponding to all elementsin a first quantity set. For example, if a carrier band is lower than 6GHz, a first quantity set is {1, 2, 4, 8}, and indexes corresponding tothe first quantity set are 0, 1, 2, and 3 (decimal), namely, 00, 01, 10,and 11 (binary); if a carrier band is higher than 6 GHz but lower than52.6 GHz, a first quantity set is {8, 16, 32, 64}, and indexescorresponding to the first quantity set are 0, 1, 2, and 3 (decimal),namely, 00, 01, 10, and ii (binary). For example, details are shown inthe following Table 1:

TABLE 1 Carrier band Index Quantity of SS blocks Lower than 6 GHz 00 101 2 10 4 11 8 Higher than 6 GHz but 00 8 lower than 52.6 GHz 01 16 1032 11 64 . . . . . . . . .

4. The network device sends the first indication information to theterminal device by using the m bits in the downlink signal, where thefirst indication information is an index corresponding to a value of thequantity n of SS blocks included in the SS burst set in thecorresponding first quantity set. For example, if the current carrierband corresponding to the SS burst set is lower than 6 GHz, thecorresponding first quantity set is {1, 2, 4, 8}. When n=4 SS blocksactually need to be sent, the first indication information is an index10, and in this case, the first indication information may be carried byusing m=2 bits, and it is obvious that m<log₂N. If the current carrierband corresponding to the SS burst set is higher than 6 GHz but lowerthan 52.6 GHz, the corresponding first quantity set is {8,16, 32, 64}.When n=32 SS blocks actually need to be sent, the first indicationinformation is an index 10, and in this case, the first indicationinformation may also be carried by using m=2 bits.

5. After receiving the first indication information, the terminal devicefirst determines, according to the protocol stipulation, the currentcarrier band corresponding to the SS burst set, and determines thecorresponding first quantity set based on the carrier band. Finally, theterminal device determines the quantity n of SS blocks according to thefirst indication information, namely, the index corresponding to thevalue of n in the corresponding first quantity set. For example, afterreceiving the first indication information, namely, an index 01, theterminal device first determines that the current carrier band is lowerthan 6 GHz, determines that the first quantity set corresponding to thecarrier band is {1, 2, 4, 8}, and finally determines n=4 based on theindex “01”. Similarly, if the terminal device determines that thecurrent carrier band is higher than 6 GHz but lower than 52.6 GHz, thequantity n of SS blocks corresponding to the index 01 is 16.

It may be further understood that if only one specified quantity of SSblocks is supported for different carrier bands, the quantity only needsto be stipulated in the protocol, and does not need to be explicitlynotified.

In Manner 1, value sets corresponding to the quantity n of SS blocks ondifferent carrier bands are separately agreed upon in advance. Inaddition, because some of possible values are specified in a value set,and the other possible values are discarded, transmission overheads canbe greatly reduced when index matching is performed to indicate thequantity n of SS blocks.

Manner 2:

In Manner 2, the SS burst set is corresponding to a same first quantityset on at least two carrier bands, and the first quantity set includes aplurality of values of a quantity of SS blocks supported in the SS burstset on each of the at least two carrier bands. That is, a protocolpre-stipulates a set of quantities n of SS blocks supported in the SSburst set on a plurality of carrier bands, and stipulates indexesseparately corresponding to elements (values of n) in the set. Then, anindex corresponding to a value of n is sent to the terminal device byusing the m bits in the downlink signal (for example, separately orjointly using a system message and signaling). A specific implementationmay be as follows:

1. The protocol stipulates maximum quantities of supported SS blocks ondifferent carrier bands. For example, when a carrier band is lower than6 GHz, a maximum value of a quantity of supported SS blocks is N=8; whena carrier band is higher than 6 GHz but lower than 52.6 GHz, a maximumvalue of a quantity of supported SS blocks is N=64. In this case,log₂N=3 for the carrier band lower than 6 GHz, and log₂N=6 for thecarrier band higher than 6 GHz but lower than 52.6 GHz.

2. The protocol stipulates all possible quantities of supported SSblocks on different carrier bands. For example, when a carrier band islower than 6 GHz, quantities of supported SS blocks are only {1, 2, 4,8}; when a carrier band is higher than 6 GHz but lower than 52.6 GHz,quantities of supported SS blocks are only {8, 16, 32, 64}. In theforegoing two cases, the protocol stipulates that the first quantity setis {1, 2, 4, 8, 16, 32, 64}, that is, values of the quantity n ofsupported SS blocks on different carrier bands are included in a sameset.

3. The network device sends the first indication information to theterminal device by using the m bits in the downlink signal, where thefirst indication information is an index corresponding to a value of thequantity n of SS blocks included in the SS burst set in the firstquantity set. For example, regardless of a current carrier band, allcarrier bands are corresponding to a same first quantity set {1, 2, 4,8, 16, 32, 64}, and indexes corresponding to the first quantity set are0, 1, 2, 3, 4, 5, and 6 (decimal), namely, 000, ow, 010, 011, 100, 101,and 110 (binary, 3 bits). In this case, m=3 bits are required fortransmitting the first indication information. For example, details areshown in the following Table 2:

TABLE 2 Carrier band Index Quantity of SS blocks Lower than 6 GHz and000 1 higher than 6 GHz but lower 001 2 than 52.6 GHz 010 4 . . . 011 8100 16 101 32 110 64 . . . . . .

4. After receiving the first indication information, the terminal devicefirst directly searches the specified first quantity set for thecorresponding quantity n based on an index of n in the first indicationinformation according to the protocol stipulation, instead of focusingon the current carrier band of the SS burst set.

It may be understood that compared with Manner 1, m is larger in Manner2. Because a quantity of elements in the set is obtained aftercombination, and is obviously greater than that before the combination,transmission overheads are slightly higher. However, because a pluralityof carrier bands share a same first quantity set, the terminal devicedoes not need to determine the current carrier band. In addition, m iscorresponding to a same value, and the network device sends the firstindication information by using a same information format.

It may be further understood that if only one specified quantity of SSblocks is supported for different carrier bands, the quantity only needsto be stipulated in the protocol, and does not need to be explicitlynotified.

In Manner 2, a value set corresponding to the quantity n of SS blocks ona plurality of carrier bands is agreed upon in advance. In addition,because some of possible values are specified in a value set, and theother possible values are discarded, transmission overheads can begreatly reduced when index matching is performed to indicate thequantity n of SS blocks.

Manner 3:

In Manner 3, the SS burst set is corresponding to different firstquantity sets in different SS burst set periods, and the first quantityset includes a plurality of values of a quantity of SS blocks supportedin the SS burst set in a current SS burst set period. That is, aprotocol pre-stipulates sets of quantities n of SS blocks separatelysupported in the SS burst set in different SS burst set periods, andstipulates indexes separately corresponding to elements (values of n) inthe sets. Then, an index corresponding to a value of n is sent to theterminal device by using the m bits in the downlink signal (for example,separately or jointly using a system message and signaling). A specificimplementation may be as follows:

1. The protocol stipulates maximum quantities of supported SS blocks indifferent SS burst set periods. For example, if an SS burst set periodis 20 ms, a maximum value of a quantity of supported SS blocks is N=8;if an SS burst set period is 80 ms, a maximum value of a quantity ofsupported SS blocks is N=64. In this case, log₂N=3 for the period 20 ms,and log₂N=6 for the period 80 ms.

2. The protocol stipulates that different SS burst set periods arecorresponding to different first quantity sets, and the first quantityset includes a plurality of values of a quantity of SS blocks supportedin the SS burst set in a current SS burst set period. For example, if anSS burst set period is 20 ms, a corresponding first quantity set is {1,2, 4, 8}, and it indicates that only 1, 2, 4, or 8 SS blocks can besupported in the SS burst set in this shorter SS burst set period; if anSS burst set period is 80 ms, a corresponding first quantity set is {8,16, 32, 64}, and it indicates that only 8, 16, 32, or 64 SS blocks canbe supported in the SS burst set in this longer SS burst set period. Itmay be understood that in this implementation, a value of m is relatedto a quantity of values of the quantity n of supported SS blocks in anSS burst set period, that is, a quantity of elements in a first quantityset corresponding to a shorter SS burst set period may be the same as ormay be different from a quantity of elements in a first quantity setcorresponding to a longer SS burst set period. If the two quantities arethe same, m is equal in different SS burst set periods, and in thiscase, the terminal device receives and parses the first indicationinformation by using same bits in different SS burst set periods. If thetwo quantities are different, m is not equal in different SS burst setperiods, and the network device needs to send the first indicationinformation by using different information formats.

3. The protocol further stipulates indexes corresponding to all elementsin a first quantity set. For example, if an SS burst set period is 20ms, a first quantity set is {1, 2, 4, 8}, and indexes corresponding tothe first quantity set are 0, 1, 2, and 3 (decimal), namely, 00, 01, 10,and 11 (binary); if an SS burst set period is 80 ms, a first quantityset is {8, 16, 32, 64}, and indexes corresponding to the first quantityset are 0, 1, 2, and 3 (decimal), namely, 00, 01, 10, and 11 (binary).For example, details are shown in the following Table 3:

TABLE 3 SS burst set period Index Quantity of SS blocks 20 ms 00 1 01 210 4 11 8 80 ms 00 8 01 16 10 32 11 64 . . . . . . . . .

4. The network device sends the first indication information to theterminal device by using the m bits in the downlink signal, where thefirst indication information is an index corresponding to a value of thequantity n of SS blocks included in the SS burst set in thecorresponding first quantity set. For example, if the current SS burstset period is 20 ms, the corresponding first quantity set is {1, 2, 4,8}. When n=4 SS blocks actually need to be sent, the first indicationinformation is an index 10, and in this case, the first indicationinformation may be carried by using m=2 bits, and it is obvious thatm<log₂N. If the current SS burst set period corresponding to the SSburst set is 8o ms, the corresponding first quantity set is {8, 16, 32,64}. When n=32 SS blocks actually need to be sent, the first indicationinformation is an index 10, and in this case, the first indicationinformation may be carried by using m=2 bits.

5. After receiving the first indication information, the terminal devicefirst determines, according to the protocol stipulation, the current SSburst set period corresponding to the SS burst set, and determines thecorresponding first quantity set based on the SS burst set period.Finally, the terminal device determines the quantity n of SS blocksaccording to the first indication information, namely, the indexcorresponding to the value of n in the corresponding first quantity set.For example, after receiving the first indication information, namely,an index 01, the terminal device first determines that the current SSburst set period is 20 ms, determines that the first quantity setcorresponding to the SS burst set period is {1, 2, 4, 8}, and finallydetermines n=4 based on the index “01”. Similarly, if the terminaldevice determines that the current SS burst set period is 80 ms, thequantity n of SS blocks corresponding to the index 01 is 16.

It may be further understood that if only one specified quantity of SSblocks is supported for different SS burst set periods, the quantityonly needs to be stipulated in the protocol, and does not need to beexplicitly notified.

In Manner 3, value sets corresponding to the quantity n of SS blocks indifferent SS burst set periods are separately agreed upon in advance. Inaddition, because some of possible values are specified in a value set,and the other possible values are discarded, transmission overheads canbe greatly reduced when index matching is performed to indicate thequantity n of SS blocks.

Manner 4:

In Manner 4, the SS burst set is corresponding to a same first quantityset in at least two SS burst set periods, and the first quantity setincludes a plurality of values of a quantity of SS blocks supported inthe SS burst set in each of the at least two SS burst set periods. Thatis, a protocol pre-stipulates a set of quantities n of SS blockssupported in the SS burst set in a plurality of SS burst set periods,and stipulates indexes separately corresponding to elements (values ofn) in the set. Then, an index corresponding to a value of n is sent tothe terminal device by using the m bits in the downlink signal (forexample, separately or jointly using a system message and signaling). Aspecific implementation may be as follows:

1. The protocol stipulates maximum quantities of supported SS blocks indifferent SS burst set periods. For example, if an SS burst set periodis 20 ms, a maximum value of a quantity of supported SS blocks is N=8;if an SS burst set period is 80 ms, a maximum value of a quantity ofsupported SS blocks is N=64. In this case, log₂N=3 for the period 20 ms,and log₂N=6 for the period 80 ms.

2. The protocol stipulates all possible quantities of supported SSblocks in different SS burst set periods. For example, when an SS burstset period is 20 ms, quantities of supported SS blocks are only {1, 2,4, 8}; when an SS burst set period is 80 ms, quantities of supported SSblocks are only {8, 16, 32, 64}. In the foregoing two cases, theprotocol stipulates that the first quantity set is {1, 2, 4, 8, 16, 32,64}, that is, values of the quantity n of supported SS blocks indifferent SS burst set periods are included in a same set.

3. The network device sends the first indication information to theterminal device by using the m bits in the downlink signal, where thefirst indication information is an index corresponding to a value of thequantity n of SS blocks included in the SS burst set in the firstquantity set. For example, regardless of a current SS burst set period,all SS burst set periods are corresponding to a same first quantity set{1, 2, 4, 8, 16, 32, 64}, and indexes corresponding to the firstquantity set are o, 1, 2, 3, 4, 5, and 6 (decimal), namely, 000, 001,010, 011, 100, 101, and 110 (binary). In this case, m=3 bits arerequired for transmitting the first indication information. For example,details are shown in the following Table 4:

TABLE 4 SS burst set period Index Quantity of SS blocks 20 ms and 80 ms000 1 . . . 001 2 010 4 011 8 100 16 101 32 110 64 . . . . . .

4. After receiving the first indication information, the terminal devicefirst directly searches the specified first quantity set for thecorresponding quantity n based on an index of n in the first indicationinformation according to the protocol stipulation, instead of focusingon the current SS burst set period of the SS burst set.

It may be understood that if only one specified quantity of SS blocks issupported for different SS burst set periods, the quantity only needs tobe stipulated in the protocol, and does not need to be explicitlynotified.

It may be further understood that compared with Manner 3, m is larger inManner 4. Because a quantity of elements in the set is obtained aftercombination, and is obviously greater than that before the combination,transmission overheads are slightly higher. However, because a pluralityof SS burst set periods share a same first quantity set, the terminaldevice does not need to determine the current SS burst set period. Inaddition, m is corresponding to a same value, and the network devicesends the first indication information by using a same informationformat.

It should be noted that in the foregoing Manner 3 and Manner 4, theterminal device may obtain and determine the current SS burst set periodby using system information and a broadcast message. This applicationprovides a method for implicitly sending SS burst set period informationby using a PBCH. The following two possible implementations areincluded:

In a possible implementation, the network device generates demodulationreference signal DMRS sequences of a corresponding physical broadcastchannel PBCH based on different SS burst set periods, and the terminaldevice determines the current SS burst set period of the SS burst setbased on the DMRS sequence. In another possible implementation, thenetwork device generates corresponding pseudo noise PN sequences basedon different SS burst set periods, and scrambles DMRSs by using the PNsequences, and the terminal device determines the current SS burst setperiod of the SS burst set based on the DMRS sequence scrambled by usingthe PN. A specific implementation may be as follows:

1. The network device generates a DMRS sequence of a corresponding PBCHbased on an SS burst set period, or generates a PN sequence based on anSS burst set period, and scrambles a DMRS by using the PN sequence.

2. The protocol pre-stipulates that different SS burst sets areassociated with different sequences. The sequences may be used as DMRSsof the PBCH or used for scrambling DMRSs. For example, in NR, SS burstset periods may be 5 ms, 10 ms, 20 ms, 40 ms, 80 ms, and 160 ms, thatis, six orthogonal or pseudo-orthogonal sequences are required. If moreperiods are to be supported, more sequences are required.

Optionally, in addition to the foregoing manner, SS burst set periodinformation may be included by using different cyclic redundancy check(CRC) masks of the PBCH, different redundancy versions of the PBCH,different shift versions of the PBCH, or the like.

3. The terminal device receives an SS block, and obtains an SS burst setperiod through correlation detection. The terminal device equalizes aDMRS by using a channel estimated based on an SSS, generatescorresponding DMRS sequences based on different SS burst set periods,and then performs correlation detection on the corresponding DMRSsequences and the equalized DMRS sequence. It is assumed that an SSburst set period with a highest correlation is an actual SS burst setperiod.

The method for performing correlation detection based on a DMRS sequencecan be faster and more accurate than a method for performing correlationdetection by using a CRC mask. After an SS burst set period is obtained,combined demodulation of PBCHs between SS blocks corresponding todifferent SS burst sets can be implemented to obtain better demodulationperformance.

In Manner 4, a value set corresponding to the quantity n of SS blocks ina plurality of SS burst set periods is agreed upon in advance. Inaddition, because some of possible values are specified in a value set,and the other possible values are discarded, transmission overheads canbe greatly reduced when index matching is performed to indicate thequantity n of SS blocks.

Type 2: The related information about n includes a parameter or an indexthat is used to calculate the quantity n of SS blocks according to aprotocol stipulation. This type of implementation may specificallyinclude the following Manner 5 to Manner 9:

Manner 5:

In Manner 5, the SS burst set includes X synchronization signal burstsSS bursts, and each SS burst includes a same quantity of SS blocks; andthe related information about n is a quantity A of SS blocks in a singleSS burst, where both X and A are integers greater than 1. That is, aprotocol pre-stipulates a specific quantity of SS bursts included in anSS burst set, and stipulates that each SS burst includes a same quantityof SS blocks. Then, the quantity A of SS blocks in the SS burst is sentto the terminal device by using the m bits in the downlink signal (forexample, separately or jointly by using a system message and signaling).A specific implementation may be as follows:

1. The protocol stipulates that each SS burst set includes X SS bursts,and stipulates that each SS burst includes a same quantity of SS blocks.For example, if the protocol stipulates X=8, each SS burst set includeseight SS bursts, and each SS burst can include only a same quantity ofSS blocks.

2. The network device sends the first indication information to theterminal device, where the related information about n included in thefirst indication information is the quantity A of SS blocks in thesingle SS burst. For example, if A=8, it indicates that each SS burstincludes eight SS blocks, that is, the network device actually transmitsA×X=64 SS blocks at this time. In this case, because a binary numbercorresponding to A=8 (decimal) that needs to be transmitted is 111 (abinary number 000 is used to indicate that a quantity of SS blocks is1), m=3. Assuming that the maximum value of n is N=64, log₂N=6, and itis obvious that m<log₂N.

3. After receiving the first indication information, the terminal deviceperforms calculation based on the quantity A of SS blocks in each SSburst in the first indication information and the fact pre-stipulated inthe protocol that an SS burst set includes X SS bursts, that is, aquantity of SS blocks included in a current SS burst set is obtained bymultiplying A by X. For example, if X=8 and A=8, through calculation,the terminal device learns that the network device actually transmitsA×X=64 SS blocks.

In Manner 5, because a quantity of SS bursts in an SS burst set isexplicitly specified, and it is stipulated that each SS burst includes asame quantity of SS blocks, only a specific quantity of SS blocks ineach SS burst needs to be notified to the terminal device, so thattransmission overheads can be greatly reduced.

Manner 6:

In Manner 6, the SS burst set includes X synchronization signal burstsSS bursts, and each SS burst includes a same quantity of SS blocks; andthe related information about n is an index corresponding to a value ofa quantity A of SS blocks in a single SS burst in a second quantity set,and the second quantity set includes a plurality of values of thequantity A of SS blocks in the single SS burst, where both X and A areintegers greater than 1. That is, a protocol pre-stipulates a specificquantity of SS bursts included in an SS burst set, and stipulates thateach SS burst includes a same quantity of SS blocks. Then, the indexcorresponding to the value of the quantity A of SS blocks in the SSburst in the predefined second quantity set is sent to the terminaldevice by using the m bits in the downlink signal (for example,separately or jointly using a system message and signaling).

A difference between this implementation and Manner 5 lies in that inManner 5, the network device sends a value (binary) of A to the terminaldevice, and in this implementation, the network device sends an indexcorresponding to a value of A in a predefined value set to the terminaldevice. Therefore, after receiving the index, the terminal device needsto perform matching based on the index in the predefined second quantityset to obtain a specific value of A. For a specific implementation,refer to the foregoing Manner 5. Details are not described herein again.

In Manner 6, a beneficial effect corresponding to Manner 5 is reserved,and transmission overheads are further reduced when only an index of aspecific quantity of SS blocks in each SS burst needs to be indicated.

Manner 7:

In Manner 7, each SS burst in the SS burst set includes Y SS blocks; andthe related information about n is a quantity B of SS bursts included inthe SS burst set, where both Y and B are integers greater than 1. Thatis, a protocol pre-stipulates that each SS burst includes a samequantity of SS blocks, and specifically stipulates a quantity of SSblocks included in each SS burst. Then, the quantity B of SS bursts inthe SS burst set is sent to the terminal device by using the m bits inthe downlink signal (for example, separately or jointly by using asystem message and signaling). A specific implementation may be asfollows:

1. The protocol stipulates that each SS burst in the SS burst setincludes Y SS blocks, that is, each SS burst includes a same quantity ofSS blocks and the quantity is Y. For example, if the protocol stipulatesY=4, each SS burst includes four SS blocks.

2. The network device sends the first indication information to theterminal device, where the related information about n included in thefirst indication information is the quantity B of SS bursts in the SSburst set. For example, if B=8, it indicates that the SS burst setincludes a total of eight SS bursts, and the network device actuallytransmits B×Y=32 SS blocks at this time. In this case, because a binarynumber corresponding to A=8 (decimal) that needs to be transmitted is111 (a binary number 000 is used to indicate that a quantity of SSblocks is i), m=3. Assuming that the maximum value of n is N=64,log₂N=6, and it is obvious that m<log₂N.

3. After receiving the first indication information, the terminal deviceperforms calculation based on the quantity B of SS bursts in the firstindication information and the fact pre-stipulated in the protocol thateach SS burst includes Y SS blocks, that is, a quantity of SS blocksincluded in a current SS burst set is obtained by multiplying B by Y.For example, if Y=4 and B=8, through calculation, the terminal devicelearns that the network device actually transmits B×Y=32 SS blocks.

In Manner 7, because a quantity of SS blocks in each SS burst isexplicitly specified, and it is stipulated that each SS burst includes asame quantity of SS blocks, only a specific quantity of SS bursts needsto be notified to the terminal device, so that transmission overheadscan be greatly reduced.

Manner 8:

In Manner 8, each SS burst in the SS burst set includes Y SS blocks; andthe related information about n is an index corresponding to a value ofa quantity B of SS bursts included in the SS burst set in a thirdquantity set, and the third quantity set includes a plurality of valuesof the quantity B of SS bursts included in the SS burst set, where bothY and B are integers greater than 1. That is, a protocol pre-stipulatesa specific quantity of SS blocks included in an SS burst, and stipulatesthat each SS burst includes a same quantity of SS blocks. Then, theindex corresponding to the value of the quantity B of SS bursts in theSS burst set in the predefined third quantity set is sent to theterminal device by using the m bits in the downlink signal (for example,separately or jointly using a system message and signaling).

A difference between this implementation and Manner 7 lies in that inManner 7, the network device sends a value (binary) of B to the terminaldevice, and in this implementation, the network device sends an indexcorresponding to a value of B in a predefined value set to the terminaldevice. Therefore, after receiving the index, the terminal device needsto perform matching based on the index in the predefined third quantityset to obtain a specific value of B. For a specific implementation,refer to the foregoing Manner 7. Details are not described herein again.

In Manner 8, a beneficial effect corresponding to Manner 7 is reserved,and transmission overheads are further reduced when only an index of aspecific quantity of SS bursts needs to be indicated.

Manner 9:

In Manner 9, the related information about n is group indexes andintra-group indexes that are of groups to which the quantity n of SSblocks belongs, and the groups are I groups obtained after H values ofthe quantity of SS blocks supported in the SS burst set are classified,where both H and I are integers greater than 1, and I is less than H;and the group indexes are carried by using Q bits in the first systemmessage and the intra-group indexes are carried by using m−Q bits in thefirst dedicated signaling, where Q is an integer greater than o. Thatis, a protocol pre-stipulates a set of quantities n of supported SSblocks in an SS burst set. Elements (values of n) in the set areclassified into one group, then index matching is performed on thegroup, and index matching is performed on elements in the group. Then,the group indexes and the intra-group indexes corresponding to thevalues of n are sent to the terminal device by using the m bits in thedownlink signal (for example, separately or jointly by using a systemmessage and signaling). A specific implementation may be as follows:

1. Assuming that quantities of SS blocks supported by the protocol are{1, 2, 4, 8, 16, 24, 32, 64}, the quantities may be classified into fourgroups (1, 2), (4, 8), (16, 24), and (32, 64), and indexing is performedby using 2 bits. The network device roughly indicates, by using the Qbits in the first system message, a group to which a current quantity ofSS blocks belongs. Before a specific quantity of SS blocks is obtained,it may be assumed that a relatively small value in a group is thequantity of SS blocks.

2. For a terminal device in an RRC_Connected mode, the network devicenotifies a specific quantity of SS blocks by using the m−Q bits in thefirst dedicated signaling. For a terminal device in an idle mode, basedon a network access requirement, an NR-SS is detected to determinewhether there is an additional SS block.

It may be understood that in the foregoing nine manners of thisapplication, because the quantity n of SS blocks is indicated by usingan index of the quantity n of SS blocks, or the quantity n of SS blocksis calculated by using a related parameter of the quantity n of SSblocks, a quantity of transmission bits is small. Therefore, when thequantity of SS blocks is being indicated, transmission overheads can bereduced, and communication efficiency is improved.

In Manner 9, a plurality of values of the quantity n of SS blocks areagreed upon in advance, the plurality of values are classified, and thenthe quantity n of SS blocks is indicated by matching a correspondingindex. In this way, not only transmission overheads can be reduced, butalso efficiency of identifying the quantity n of SS blocks by theterminal device can be improved.

In the foregoing nine manners, classification is mainly performed basedon different content specifically included in the related informationabout n. The following specifically describes how the network devicespecifically enables the m bits in the downlink signal to carry thefirst indication information.

With reference to any one of the foregoing Manner 1 to Manner 9, thedownlink signal includes a first system message and first dedicatedsignaling; and the first indication information is carried by using Qbits in the first system message and m−Q bits in the first dedicatedsignaling together, where Q is an integer greater than o, and Q is lessthan m. That is, a protocol stipulates that the m bits in the downlinksignal are divided into two parts for transmission, to further reduceoverheads of a system message or signaling. In a possibleimplementation, the first system message is a message carried on thephysical broadcast channel PBCH or remaining minimum system informationRMSI; and/or the first dedicated signaling is any one of radio resourcecontrol RRC signaling, Media Access Control baseband resource MAC CEsignaling, downlink control information DCI signaling, and presetdedicated signaling that is used to carry the related information aboutn.

With reference to any one of the foregoing Manner 1 to Manner 9, thedownlink signal includes a second system message, the second systemmessage includes a plurality of types of messages, and the plurality oftypes of messages include at least a message carried on the physicalbroadcast channel PBCH and remaining minimum system information; and thefirst indication information is carried by using m bits in at least oneof the plurality of types of messages. That is, the m bits of the firstindication information may be carried by using any one of the pluralityof types of system messages, or may be carried by using two or moresystem messages. For example, all the m bits are carried in the messagecarried on the PBCH, or some of the m bits are carried in the messagecarried on the PBCH and some of the m bits are carried in another systemmessage. This is not specifically limited in this application.

It should be noted that the first system message may be the same as ordifferent from the second system message, and this is not specificallylimited in this application. The first system message and the secondsystem message may further include a paging message and a systeminformation block (SIB).

This application further resolves a technical problem that excessivesystem message overheads are caused by transmitting indicationinformation by using a system message. With reference to the informationreceiving and sending method embodiment provided in this application,the following specifically analyzes and resolves the foregoing technicalproblem proposed in this application.

FIG. 4 is a schematic flowchart of another information sending andreceiving method according to an embodiment of this application. Themethod may be applied to the communications system in FIG. 2. Thefollowing describes the method from a perspective of interaction betweena network device and a terminal device with reference to FIG. 4, and themethod may include the following steps S401 to S403.

Step S401: A network device sends second indication information to aterminal device.

Specifically, the second indication information is carried by using abits in a downlink system message and b bits associated with a downlinkreference signal, and the second indication information is used toindicate a quantity n of synchronization signal blocks SS blocksincluded in a synchronization signal burst set SS burst set, wherea+b=log₂N, N is a maximum value of a quantity of SS blocks supported inthe SS burst set, a, b, and n all are integers greater than 0, and n isless than or equal to N. The second indication information in thisembodiment is different from the first indication information in theforegoing embodiment corresponding to FIG. 3, because the firstindication information corresponding to FIG. 3 is related informationabout the quantity n of SS blocks, but the second indication informationin this embodiment is the quantity n of SS blocks (namely, a binarynumber of n) instead of the related information. In addition, in thisembodiment, the second indication information is distributed in thedownlink system message and the downlink reference signal for jointtransmission, thereby reducing overheads of one of the message or thesignal.

In a possible implementation, the downlink system message is a messagecarried on a physical broadcast channel PBCH, and the downlink referencesignal is a demodulation reference signal DMRS sequence of the PBCH; andthe second indication information is carried by using a bits in themessage carried on the PBCH and b bits associated with the DMRSsequence, where the b bits associated with the DMRS sequence include bitinformation used to generate the DMRS sequence or bit information usedto generate a PN sequence for scrambling the DMRS sequence. That is,some of bits of the quantity n of SS blocks are explicitly sent in themessage carried on the PBCH, and the other bits are implicitly sent inthe demodulation reference signal DMRS sequence of the PBCH. Details maybe as follows:

1. The network device directly places Q bits of information about thequantity n of SS blocks on the PBCH, where remaining bit information ispresented in an implicit manner.

It is assumed that the quantity n of SS blocks needs to be representedby using m bits. A value of m may be related to a quantity of actuallysent SS blocks in the SS burst set, or may be related to maximumquantities of supported SS blocks on different carrier bands. Forexample, when a carrier band is lower than 6 GHz, m is 3, and when acarrier band is higher than 6 GHz but lower than 52.6 GHz, m is 6. Inthis case, to uniformly design a PBCH on the high band and a PBCH on thelow band, a value of Q is 3, that is, 3 bits of information about thequantity n of SS blocks are placed on the PBCH, and m−3 bits ofinformation are presented in an implicit manner. For another example, Qbits are explicitly carried on the PBCH, and m−Q bits are carried in animplicit manner. The network device may further distinguish, by using 1bit of information, whether the implicitly sent bit information needs tobe solved. The 1 bit of information may be directly associated with acarrier band, and is not explicitly sent, that is, the M−Q bits ofinformation do not need to be solved for the low band but need to besolved for the high band; or the 1 bit of information is implicitly senttogether with the M−Q bits of information, in other words, M−Q+1 bits ofinformation are implicitly sent; or the 1 bit of information isexplicitly sent on the PBCH. Other manners are not excluded.

There may be various implicit manners. For example, (1) the remainingbit information is distinguished by using different CRC masks of thePBCH, different redundancy versions of the PBCH, different cyclic shiftversions of the PBCH, or the like; (2) DMRSs of the PBCH are scrambledby using different designed sequences or different DMRS sequences areused to distinguish the implicitly carried bit information. If 3 bits ofinformation need to be distinguished, eight different versions in thecorresponding manner are required. In this case, for the low band, all 3bits are included in the PBCH, that is, 000 is represented in animplicit manner.

2. The terminal device receives the PBCH and detects the PBCH in acorresponding manner, to obtain information about the quantity n of SSblocks.

This implementation can reduce resource overheads compared with a mannerin which all 6 bits are directly placed on the PBCH, and can reducecomplexity of blind detection or detection compared with a manner inwhich all information bits are represented by blindly detecting the PBCHor detecting a DMRS of the PBCH.

Step S02: The terminal device receives the second indication informationsent by the network device.

Specifically, the second indication information is carried by using thea bits in the downlink system message and the b bits in the downlinkreference signal, and the second indication information is used toindicate the quantity n of synchronization signal blocks SS blocksincluded in the synchronization signal burst set SS burst set, wherea+b=log₂N, N is the maximum value of the quantity of SS blocks supportedin the SS burst set, a, b, and n all are integers greater than 0, and nis less than or equal to N.

Step S403: The terminal device determines the quantity n of SS blocksaccording to the second indication information.

In this embodiment of this application, the second indicationinformation is distributed in the downlink system message and thedownlink reference signal for joint transmission, thereby reducingoverheads of one of the message or the signal.

This application further provides other implementations of indicatingthe quantity n of SS blocks or the related information about n, and thefollowing five implementations are mainly included:

Implementation 1: A quantity of SS blocks is distributed in a pluralityof system messages or a plurality of pieces of signaling for jointtransmission. In this embodiment, a manner of combining a PBCH with RMSIis used as an example. Specific steps are as follows:

1. The network device represents the quantity n of SS blocks by using abinary number of m bits, where 2^(m) is greater than or equal to amaximum quantity of SS blocks supported in the SS burst set in NR or amaximum quantity of supported SS blocks on the carrier band or in the SSburst set period, Q bits in the binary number are sent on the PBCH, andremaining m−Q bits are sent in the RMSI.

2. The terminal device obtains the quantity of SS blocks by receivingthe PBCH and the RMSI.

In this process, if a protocol stipulates that the Q bits can representall cases of the quantity of SS blocks in low-frequency communication,it means that remaining information about the quantity of SS blocksneeds to be obtained from the RMSI only in high-frequency communication.If the protocol does not specify whether the Q bits have the foregoingcapability, the information about the quantity of SS blocks can beobtained only by receiving the PBCH and the RMSI information duringcommunication. In addition, 1 bit of information may be added to thePBCH to indicate whether the RMSI needs to be additionally received toobtain all information about the quantity of SS blocks. In this case, ifonly a relatively small quantity of SS blocks are actually used, theterminal device can obtain the quantity of SS blocks as soon as possibleby using the 1 bit of identification information.

In Implementation 1, the quantity of SS blocks is distributed in aplurality of system messages or a plurality of pieces of signaling forjoint transmission, thereby reducing transmission overheads of a systemmessage or signaling.

Implementation 2: On a carrier band or in an SS burst set period, aprotocol stipulates that a maximum quantity of SS blocks that can besupported is N, and stipulates a corresponding frame structure. If thequantity n of actually configured SS blocks is less than N, and SSblocks discontinuously appear in the SS burst set, a location of eachactivated SS block needs to be notified. Details are as follows:

1. The network device may generate a sequence based on configuration ofan SS block in a current SS burst set and an active or inactive state ofthe SS block. If an SS block in the sequence is activated, a locationcorresponding to the sequence is set to 1; otherwise, the correspondinglocation is set to o. The sequence may also be sent in a manner similarto the manners in Embodiment 1 and Embodiment 2 in which the PBCH andthe RMSI are separately or jointly used. In addition, if severaldifferent activation modes are stipulated in the protocol, for example,an SS block with an odd number is valid and an SS block at an intervalof X is valid, a corresponding mode needs to be notified, therebyreducing signaling overheads.

2. The terminal device obtains the sequence or the corresponding mode byusing a broadcast message or a system message, and therefore may inferthe quantity of SS blocks according to the protocol stipulation.

In Implementation 2, an activated SS block can be flexibly indicated.The terminal device may skip a non-activated SS block based on the framestructure defined in the protocol and the obtained sequence. Adisadvantage of Implementation 2 is that a relatively large quantity ofbits may need to be used. For example, 64 SS blocks require a maximum of64 bits. Overheads can be properly reduced by predefining some modes.

Implementation 3: The terminal device obtains, through blind detection,a quantity of bits that are used to indicate a quantity of actuallytransmitted SS blocks, and further obtains information about thecorresponding bits in the corresponding information, to obtain thequantity of SS blocks. Details are as follows:

1. The information about the quantity of SS blocks may be transmitted byseparately or jointly using a system message and signaling. A protocolstipulates that a quantity of some or all of bits in the quantity(binary) of SS blocks is associated with a decoding manner oftransmission information in a specific manner. For example, differentCRC masks of the PBCH, different redundancy versions of the PBCH, ordifferent cyclic shift versions of the PBCH are used to indicatedifferent bit quantities.

2. The terminal device performs blind detection on the correspondingsystem information or signaling, that is, performs verification by usingdifferent CRC masks or performs decoding by using different redundancyversions, different cyclic shift versions, or the like, to obtain thequantity of some or all of bits in the corresponding quantity of SSblocks, and obtain the information about the corresponding quantity.Further, information about a quantity of other remaining bits isobtained, to finally obtain the quantity of SS blocks.

In Implementation 3, a quantity of bits of an SS block time index (SSblock time index) may also be associated with a decoding manner of thePBCH. The terminal device may learn of a specific data bit width of theSS block time index by blindly detecting the PBCH, to solve the SS blocktime index. In this way, when the quantity of SS blocks in the SS burstset is relatively small, few data bits can be used to represent the SSblock time index without explicit signaling overheads.

Implementation 4: The terminal device obtains a quantity of bits of anSS block time index by detecting a DMRS sequence of the PBCH. Detailsare as follows:

1. A protocol stipulates that quantities of bits of different SS blocktime indexes are associated with different new sequences, for example, atertiary SS (TSS) sequence. The network device scrambles the DMRS of thePBCH by using a corresponding new sequence, or sends a new sequence asthe DMRS of the PBCH. Because a quantity of bits of an SS block timeindex is much less than the quantity of SS blocks, few new sequences arerequired.

2. The terminal device receives the PBCH, performs channel equalizationon the obtained DMRS sequence, and then performs correlation detectionon the DMRS sequence obtained after the channel equalization and DMRSsequences scrambled by using different assumed new sequences or performscorrelation detection on the DMRS sequence obtained after the channelequalization and different assumed new sequences, to obtain used newsequences and the corresponding quantity of bits representing the SSblock time index.

The terminal device needs to perform such blind detection only wheninitially accessing a network or re-accessing a network. For a connecteduser, if the quantity of bits of the SS block time index changes, thequantity of bits of the SS block time index may be notified in advanceby using dedicated signaling or through broadcasting.

In addition, the quantity of bits of the SS block time index may also beused by the terminal device to perform feedback, thereby reducingoverheads.

The terminal device may obtain, by using the quantity of bits of the SSblock time index, a maximum quantity of supported SS blocks in currentconfiguration.

In Implementation 4, the terminal device can obtain, by using thequantity of bits of the SS block time index, the maximum quantity of SSblocks supported in the SS burst set in the current configuration.

Implementation 5: A part of bit information of an SS block time index isexplicitly set on the PBCH, and the other part of bit information issent in an implicit manner. Details are as follows:

1. The network device directly places Q bits of information about the SSblock time index on the PBCH, where remaining bit information ispresented in an implicit manner.

It is assumed that the SS block time index needs to be represented byusing M bits. A value of M may be related to a quantity of actually sentSS blocks in the SS burst set, or may be related to maximum quantitiesof supported SS blocks on different carrier bands. For example, when acarrier band is lower than 6 GHz, M is 3, and when a carrier band ishigher than 6 GHz but lower than 52.6 GHz, M is 6. In this case, touniformly design a PBCH on the high band and a PBCH on the low band, avalue of Q is 3, that is, 3 bits of information about the SS block timeindex are placed on the PBCH, and M−3 bits of information are presentedin an implicit manner. For another example, Q bits are explicitlycarried on the PBCH, and M−Q bits are carried in an implicit manner. Thenetwork device may further distinguish, by using 1 bit of information,whether the implicitly sent bit information needs to be solved. The 1bit of information may be directly associated with a carrier band, andis not explicitly sent, that is, the M−Q bits of information do not needto be solved for the low band but need to be solved for the high band;or the 1 bit of information is implicitly sent together with the M−Qbits of information, in other words, M−Q+1 bits of information areimplicitly sent; or the 1 bit of information is explicitly sent on thePBCH. Other manners are not excluded. In addition, if all informationabout the quantity of SS blocks is carried on the PBCH, the terminaldevice may further infer, by using the quantity of SS blocks, whetherthe implicitly sent information has actual significance.

There may be various implicit manners. For example, (1) the remainingbit information is distinguished by using different CRC masks of thePBCH, different redundancy versions of the PBCH, different cyclic shiftversions of the PBCH, or the like; (2) DMRSs of the PBCH are scrambledby using different designed sequences or different DMRS sequences areused to distinguish the implicitly carried bit information. If 3 bits ofinformation needs to be distinguished, eight different versions in thecorresponding manner are required. In this case, for the low band, all 3bits are included in the PBCH, that is, 000 is represented in animplicit manner.

2. The terminal device receives the PBCH and detects the PBCH in acorresponding manner, to obtain information about the SS block timeindex.

Implementation 5 can reduce resource overheads compared with a manner inwhich all 6 bits are directly placed on the PBCH, and can reducecomplexity of blind detection or detection compared with a manner inwhich all information bits are represented by blindly detecting the PBCHor detecting a DMRS of the PBCH.

The foregoing describes the method in the embodiments of thisapplication in detail, and the following provides a related apparatus inthe embodiments of this application.

FIG. 5 is a schematic structural diagram of a network device accordingto an embodiment of this application. The network device 10 may includea communications unit 101 and a processing unit 102. Detaileddescriptions of each unit are as follows:

The communications unit 101 is configured to send first indicationinformation to a terminal device, where the first indication informationis carried by using m bits in a downlink signal, and the firstindication information includes related information indicating aquantity n of synchronization signal blocks SS blocks included in asynchronization signal burst set SS burst set, where m<log₂N, N is amaximum value of a quantity of SS blocks supported in the SS burst set,both m and n are integers greater than 1, and n is less than or equal toN.

Optionally, the related information about n is an index corresponding toa value of n in a first quantity set, and the first quantity setincludes a plurality of values of the quantity of SS blocks supported inthe SS burst set.

Optionally, the SS burst set is corresponding to different firstquantity sets on different carrier bands, and that the first quantityset includes a plurality of values of the quantity of SS blockssupported in the SS burst set includes:

the first quantity set includes a plurality of values of a quantity ofSS blocks supported in the SS burst set on a current carrier band.

Optionally, the SS burst set is corresponding to a same first quantityset on at least two carrier bands, and that the first quantity setincludes a plurality of values of the quantity of SS blocks supported inthe SS burst set includes:

the first quantity set includes a plurality of values of a quantity ofSS blocks supported in the SS burst set on each of the at least twocarrier bands.

Optionally, the SS burst set is corresponding to different firstquantity sets in different SS burst set periods, and that the firstquantity set includes a plurality of values of the quantity of SS blockssupported in the SS burst set includes:

the first quantity set includes a plurality of values of a quantity ofSS blocks supported in the SS burst set in a current SS burst setperiod.

Optionally, the SS burst set is corresponding to a same first quantityset in at least two SS burst set periods, and that the first quantityset includes a plurality of values of the quantity of SS blockssupported in the SS burst set includes:

the first quantity set includes a plurality of values of a quantity ofSS blocks supported in the SS burst set in each of the at least two SSburst set periods.

Optionally, the network device 10 further includes:

a processing unit 102, configured to: generate demodulation referencesignal DMRS sequences of a corresponding physical broadcast channel PBCHbased on different SS burst set periods; or generate correspondingpseudo noise PN sequences based on different SS burst set periods, andscramble DMRSs by using the PN sequences.

Optionally, the SS burst set includes X synchronization signal bursts SSbursts, and each SS burst includes a same quantity of SS blocks; and therelated information about n is a quantity A of SS blocks in a single SSburst, where both X and A are integers greater than 1; or each SS burstin the SS burst set includes Y SS blocks; and the related informationabout n is a quantity B of SS bursts included in the SS burst set, whereboth Y and B are integers greater than 1.

Optionally, the SS burst set includes X synchronization signal bursts SSbursts, and each SS burst includes a same quantity of SS blocks; and therelated information about n is an index corresponding to a value of aquantity A of SS blocks in a single SS burst in a second quantity set,and the second quantity set includes a plurality of values of thequantity A of SS blocks in the single SS burst, where both X and A areintegers greater than 1; or each SS burst in the SS burst set includes YSS blocks; and the related information about n is an index correspondingto a value of a quantity B of SS bursts included in the SS burst set ina third quantity set, and the third quantity set includes a plurality ofvalues of the quantity B of SS bursts included in the SS burst set,where both Y and B are integers greater than 1.

Optionally, the downlink signal includes a first system message andfirst dedicated signaling; and that the first indication information iscarried by using m bits in a downlink signal includes: the firstindication information is carried by using Q bits in the first systemmessage and m−Q bits in the first dedicated signaling together, where Qis an integer greater than 0, and Q is less than m.

Optionally, the first system message is a message carried on thephysical broadcast channel PBCH or remaining minimum system informationRMSI; and/or the first dedicated signaling is any one of radio resourcecontrol RRC signaling, Media Access Control baseband resource MAC CEsignaling, downlink control information DCI signaling, and presetdedicated signaling that is used to carry the related information aboutn.

Optionally, the downlink signal includes a second system message, thesecond system message includes a plurality of types of messages, and theplurality of types of messages include at least a message carried on thephysical broadcast channel PBCH and remaining minimum systeminformation; and that the first indication information is carried byusing m bits in a downlink signal includes: the first indicationinformation is carried by using m bits in at least one of the pluralityof types of messages.

Optionally, the related information about n is group indexes andintra-group indexes that are of groups to which the quantity n of SSblocks belongs, and the groups are I groups obtained after H values ofthe quantity of SS blocks supported in the SS burst set are classified,where both H and I are integers greater than 1, and I is less than H;and that the first indication information is carried by using m bits ina downlink system signal includes: the group indexes are carried byusing Q bits in the first system message and the intra-group indexes arecarried by using m−Q bits in the first dedicated signaling, where Q isan integer greater than 0.

It should be noted that for functions of the functional units in thenetwork device 10 described in this embodiment of this application,refer to the related descriptions of the foregoing method embodiment inFIG. 1 to FIG. 4. Details are not described herein again.

FIG. 6 is a schematic structural diagram of a terminal device accordingto an embodiment of this application. The terminal device 20 may includea communications unit 201 and a processing unit 202. Detaileddescriptions of each unit are as follows:

The communications unit 201 is configured to receive first indicationinformation sent by a network device, where the first indicationinformation is carried by using m bits in a downlink signal, and thefirst indication information includes related information indicating aquantity n of synchronization signal blocks SS blocks included in asynchronization signal burst set SS burst set, where m<log₂N, and N is amaximum value of a quantity of SS blocks supported in the SS burst set.

The processing unit 202 is configured to determine the quantity n of SSblocks according to the first indication information.

Optionally, the related information about n is an index corresponding toa value of n in a first quantity set, and the first quantity setincludes a plurality of values of the quantity of SS blocks supported inthe SS burst set.

That the processing unit 202 is configured to determine the quantity nof SS blocks according to the first indication information isspecifically:

determining the quantity n of SS blocks based on the first quantity setand the corresponding index.

Optionally, the SS burst set is corresponding to different firstquantity sets on different carrier bands, and the processing unit isfurther configured to:

before determining the quantity n of SS blocks according to the firstindication information, determine a current carrier band of the SS burstset, and determine a corresponding first quantity set based on thedetermined carrier band.

Optionally, the SS burst set is corresponding to different firstquantity sets in different SS burst set periods, and the processing unitis further configured to:

before determining the quantity n of SS blocks according to the firstindication information, determine a current SS burst set period of theSS burst set, and determine a corresponding first quantity set based onthe determined SS burst set period.

Optionally, demodulation reference signal DMRS sequences that are of acorresponding physical broadcast channel PBCH and that are generated indifferent SS burst set periods are different; or DMRS sequences that arescrambled by using corresponding pseudo noise PN sequences and that aregenerated in different SS burst set periods are different. That theprocessing unit 202 is configured to determine a current SS burst setperiod of the SS burst set is specifically: determining the current SSburst set period of the SS burst set based on the DMRS sequence or theDMRS sequence scrambled by using the PN sequence.

It should be noted that for functions of the functional units in theterminal device 20 described in this embodiment of this application,refer to the related descriptions of the foregoing method embodiment inFIG. 1 to FIG. 4. Details are not described herein again.

FIG. 7 is a schematic structural diagram of another network deviceaccording to an embodiment of this application. The network device 30may include a communications unit 301. Detailed descriptions of eachunit are as follows:

The communications unit 301 is configured to send second indicationinformation to a terminal device, where the second indicationinformation is carried by using a bits in a downlink system message andb bits associated with a downlink reference signal, and the secondindication information is used to indicate a quantity n ofsynchronization signal blocks SS blocks included in a synchronizationsignal burst set SS burst set, where a+b=log₂N, N is a maximum value ofa quantity of SS blocks supported in the SS burst set, a, b, and n allare integers greater than 0, and n is less than or equal to N.

Optionally, the downlink system message is a message carried on aphysical broadcast channel PBCH, and the downlink reference signal is ademodulation reference signal DMRS sequence of the PBCH; and that thesecond indication information is carried by using a bits in a downlinksystem message and b bits associated with a downlink reference signalincludes: the second indication information is carried by using a bitsin the message carried on the PBCH and b bits associated with the DMRSsequence, where the b bits associated with the DMRS sequence include bitinformation used to generate the DMRS sequence or bit information usedto generate a PN sequence for scrambling the DMRS sequence.

It should be noted that for functions of the functional units in thenetwork device 30 described in this embodiment of this application,refer to the related descriptions of the foregoing method embodiment inFIG. 1 to FIG. 4. Details are not described herein again.

FIG. 8 is a schematic structural diagram of another terminal deviceaccording to an embodiment of this application. The network device mayinclude a communications unit 401 and a processing unit 402. Detaileddescriptions of each unit are as follows:

The communications unit 401 is configured to receive second indicationinformation sent by a network device, where the second indicationinformation is carried by using a bits in a downlink system message andb bits associated with a downlink reference signal, and the secondindication information is used to indicate a quantity n ofsynchronization signal blocks SS blocks included in a synchronizationsignal burst set SS burst set, where a+b=log₂N, N is a maximum value ofa quantity of SS blocks supported in the SS burst set, a, b, and n allare integers greater than 0, and n is less than or equal to N.

The processing unit 402 is configured to determine, by the terminaldevice, the quantity n of SS blocks according to the second indicationinformation.

Optionally, the downlink system message is a message carried on aphysical broadcast channel PBCH, and the downlink reference signal is ademodulation reference signal DMRS sequence of the PBCH; and that thesecond indication information is carried by using a bits in a downlinksystem message and b bits associated with a downlink reference signalincludes: the second indication information is carried by using a bitsin the message carried on the PBCH and b bits associated with the DMRSsequence, where the b bits associated with the DMRS sequence include bitinformation used to generate the DMRS sequence or bit information usedto generate a PN sequence for scrambling the DMRS sequence.

It should be noted that for functions of the functional units in theterminal device 40 described in this embodiment of this application,refer to the related descriptions of the foregoing method embodiment inFIG. 1 to FIG. 4. Details are not described herein again.

FIG. 9 is a schematic structural diagram of a device according to anembodiment of this application. The network device 10, the terminaldevice 20, the network device 30, and the terminal device 40 each may beimplemented by using a structure shown in FIG. 9. The device 50 includesat least one processor 501, at least one memory 502, and at least onecommunications interface 503. In addition, the device may furtherinclude general components such as an antenna, and details are notdescribed herein.

The processor 501 may be a general-purpose central processing unit(CPU), a microprocessor, an application-specific integrated circuit(ASIC), or one or more integrated circuits for controlling execution ofthe foregoing solution program.

The communications interface 503 is configured to communicate withanother device or a communications network, such as the Ethernet, aradio access network (RAN), or a wireless local area network (WLAN).

The memory 502 may be a read-only memory (ROM), another type of staticstorage device that can store static information and an instruction, arandom access memory (RAM), or another type of dynamic storage devicethat can store information and an instruction; or may be an electricallyerasable programmable read-only memory (EEPROM), a compact discread-only memory (CD-ROM) or another optical disk storage, an opticaldisc storage (including a compact optical disc, a laser disc, an opticaldisc, a digital versatile disc, a Blu-ray disc, or the like), a magneticdisk storage medium or another magnetic storage device, or any othermedium that can be configured to carry or store expected program code ina form of an instruction or a data structure and that can be accessed bya computer. This does not constitute a limitation herein. The memory mayexist independently and is connected to the processor through a bus. Thememory may also be integrated with the processor.

The memory 502 is configured to store application program code forexecuting the foregoing solution, and the processor 501 controls theexecution. The processor 501 is configured to execute the applicationprogram code stored in the memory 1202.

When the device shown in FIG. 9 is the network device 10, the codestored in the memory 502 may perform the foregoing information sendingmethod, for example, sending first indication information to a terminaldevice, where the first indication information is carried by using mbits in a downlink signal, and the first indication information includesrelated information indicating a quantity n of synchronization signalblocks SS blocks included in a synchronization signal burst set SS burstset, where m<log₂N, N is a maximum value of a quantity of SS blockssupported in the SS burst set, both m and n are integers greater than 1,and n is less than or equal to N.

When the device shown in FIG. 9 is the terminal device, the code storedin the memory 502 may perform the foregoing visible light-basedcommunication method performed by a coordinator, for example, receivingfirst indication information sent by a network device, where the firstindication information is carried by using m bits in a downlink signal,and the first indication information includes related informationindicating a quantity n of synchronization signal blocks SS blocksincluded in a synchronization signal burst set SS burst set, wherem<log₂N, and N is a maximum value of a quantity of SS blocks supportedin the SS burst set; and determining the quantity n of SS blocksaccording to the first indication information.

When the device shown in FIG. 9 is the network device 30, the codestored in the memory 502 may perform the foregoing information sendingmethod, for example, sending second indication information to a terminaldevice, where the second indication information is carried by using abits in a downlink system message and b bits associated with a downlinkreference signal, and the second indication information is used toindicate a quantity n of synchronization signal blocks SS blocksincluded in a synchronization signal burst set SS burst set, wherea+b=log₂N, N is a maximum value of a quantity of SS blocks supported inthe SS burst set, a, b, and n all are integers greater than o, and n isless than or equal to N.

When the device shown in FIG. 9 is the network device 30, the codestored in the memory 502 may perform the foregoing information sendingmethod, for example, receiving second indication information sent by anetwork device, where the second indication information is carried byusing a bits in a downlink system message and b bits associated with adownlink reference signal, and the second indication information is usedto indicate a quantity n of synchronization signal blocks SS blocksincluded in a synchronization signal burst set SS burst set, wherea+b=log₂N, N is a maximum value of a quantity of SS blocks supported inthe SS burst set, a, b, and n all are integers greater than 0, and n isless than or equal to N; and determining the quantity n of SS blocksaccording to the second indication information.

It should be noted that for functions of the functional units in thenetwork device 10, the terminal device 20, the network device 30, andthe terminal device 4o described in the embodiments of this application,refer to the related descriptions of the foregoing method embodiment inFIG. 1 to FIG. 4. Details are not described herein again.

An embodiment of this application further provides a computer storagemedium. The computer storage medium may store a program, and when theprogram is executed, some or all steps of any information sending andreceiving method recorded in the foregoing method embodiments areperformed.

An embodiment of this application further provides a computer program,and the computer program includes an instruction. When the computerprogram is executed by a computer, the computer can perform some or allsteps of any information sending and receiving method.

In the foregoing embodiments, the descriptions of the embodiments haverespective focuses. For a part that is not described in detail in anembodiment, refer to related descriptions in other embodiments.

It should be noted that for brief description, the foregoing methodembodiments are represented as a series of actions. However, personsskilled in the art should appreciate that this application is notlimited to the described order of the actions, because according to thisapplication, some steps may be performed in other orders orsimultaneously. It should be further appreciated by persons skilled inthe art that the embodiments described in this specification all belongto example embodiments, and the involved actions and modules are notnecessarily required by this application.

In the several embodiments provided in this application, it should beunderstood that the disclosed apparatuses may be implemented in othermanners. For example, the described apparatus embodiment is merely anexample. For example, the unit division is merely logical functiondivision and may be other division in actual implementation. Forexample, a plurality of units or components may be combined orintegrated into another system, or some features may be ignored or notperformed. In addition, the displayed or discussed mutual couplings ordirect couplings or communication connections may be implemented throughsome interfaces. The indirect couplings or communication connectionsbetween the apparatuses or units may be implemented in electronic orother forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected based on actualrequirements to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of this application maybe integrated into one processing unit, or each of the units may existalone physically, or two or more units are integrated into one unit. Theintegrated unit may be implemented in a form of hardware, or may beimplemented in a form of a software functional unit.

When the foregoing integrated unit is implemented in the form of asoftware functional unit and sold or used as an independent product, theintegrated unit may be stored in a computer readable storage medium.Based on such an understanding, the technical solutions in thisapplication essentially, or the part contributing to the prior art, orall or some of the technical solutions may be implemented in the form ofa software product. The computer software product is stored in a storagemedium and includes several instructions for instructing a computerdevice (which may be a personal computer, a server, or a network device,and may be specifically a processor in a computer device) to perform allor some steps of the foregoing methods described in the embodiments ofthis application. The foregoing storage medium may include any mediumthat can store program code, such as a USB flash drive, a removable harddisk, a magnetic disk, an optical disc, a read-only memory (ROM forshort), or a random access memory (RAM for short).

The foregoing embodiments are merely intended for describing thetechnical solutions in this application, but not for limiting thisapplication. Although this application is described in detail withreference to the foregoing embodiments, persons of ordinary skill in theart should understand that they may still make modifications to thetechnical solutions described in the foregoing embodiments or makeequivalent replacements to some technical features thereof, withoutdeparting from the spirit and scope of the technical solutions in theembodiments of this application.

1. An information sending method, wherein the method comprises:enabling, by a network device, a physical broadcast channel (PBCH) tocarry Q bits that are used to indicate a synchronization signal (SS)block time index, the SS block time index comprising M bits, (M−Q) bitsof the M bits being implicitly carried by using demodulation referencesignal (DMRS) sequences of the PBCH, M being a first integer greaterthan 0, and Q being a second integer greater than 0; and sending thePBCH to a terminal device.
 2. The method according to claim 1, whereinthe Q bits are explicitly carried on the PBCH.
 3. The method accordingto claim 1, wherein the (M−Q) bits of the M bits correspond to one ofeight different DMRS sequences.
 4. The method according to claim 1,wherein a value of M is associated with a quantity of SS blocks sent inan SS burst set.
 5. The method according to claim 1, wherein a value ofM is associated with a maximum quantity of SS block supported by adifferent carrier band.
 6. The method according to claim 1, wherein Q is3 and M is
 6. 7. An information receiving method, wherein the methodcomprises: receiving, by a terminal, a physical broadcast channel(PBCH); detecting, by the terminal, the PBCH; and obtaining, by theterminal, a synchronization signal (SS block) time index, the SS blocktime index comprising M bits, Q bits of the M bits used to indicate theSS block time index being carried on the PBCH, and (M−Q) bits of the Mbits being implicitly carried by using demodulation reference signal(DMRS) sequences of the PBCH, M being a first integer greater than 0,and Q being a second integer greater than
 0. 8. The method according toclaim 7, wherein the Q bits are explicitly carried on the PBCH.
 9. Themethod according to claim 7, wherein the (M−Q) bits of the M bitscorrespond to one of eight DMRS sequences.
 10. The method according toclaim 7, wherein a value of M is associated with a quantity of SS blockssent in an SS burst set.
 11. The method according to claim 7, wherein avalue of M is associated with a maximum quantity of SS blocks supportedby a different carrier band.
 12. The method according to claim 7,wherein Q is 3 and M is
 6. 13. The method according to claim 7, whereinthe obtaining the information about the SS block time index comprises:detecting, by the terminal, the PBCH and obtaining a data bits width ofthe PBCH; and obtaining, by the terminal, the SS block time indexaccording to the data bits width of the PBCH.
 14. The method accordingto claim 7, wherein the DMRS of the PBCH is scrambled by a tertiarysequence (TSS).
 15. The method according to claim 7, wherein the PBCHfurther comprises 1 bit indicating whether the (M−Q) bits need to besolved.
 16. A network device, comprising: one or more memoriesconfigured to store instructions; and one or more processors coupled tothe one or more memories and configured to execute the instructions tocause the network device to: enable a physical broadcast channel (PBCH)to carry Q bits that are used to indicate a synchronization signal (SS)block time index, wherein the SS block time index comprises M bits,wherein (M−Q) bits of the M bits are implicitly carried by usingdemodulation reference signal (DMRS) sequences of the PBCH, and whereinM is a first integer greater than 0 and Q is a second integer greaterthan 0; and a communications unit, configured to send the PBCH to aterminal.
 17. The network device according to claim 16, wherein the Qbits are explicitly carried on the PBCH.
 18. The network deviceaccording to claim 16, wherein the (M−Q) bits correspond to one of eightdifferent DMRS sequences.
 19. The network device according to claim 16,wherein a value of M is associated with a quantity of SS blocks sent inan SS burst set.
 20. The network device according to claim 16, wherein avalue of M is associated with a maximum quantity of SS blocks supportedby a different carrier band.
 21. The network device according to claim16, wherein Q is 3, and M is
 6. 22. A terminal device, comprising: oneor more memories configured to store instructions; and one or moreprocessors coupled to the one or more memories and configured to executethe instructions to cause the terminal device to: receive a physicalbroadcast channel (PBCH); detect the PBCH; and obtain information abouta synchronization signal (SS) block time index, wherein the SS blocktime index comprises M bits, wherein Q bits of the M bits that are usedto indicate the SS block time index are carried on the PBCH, wherein(M−Q) bits of the M bits are implicitly carried by using differentdemodulation reference signal (DMRS) sequences of the PBCH, and whereinM is a first integer greater than 0, and Q is second integer greaterthan
 0. 23. The terminal device according to claim 22, wherein the Qbits are explicitly carried on the PBCH.
 24. The terminal deviceaccording to claim 22, wherein the (M−Q) bits correspond to one of eightdifferent DMRS sequences.
 25. The terminal device according to claim 22,wherein a value of M is associated with a quantity of SS blocks actuallysent in an SS burst set.
 26. The terminal device according to claim 22,wherein a value of M is associated with a maximum quantity of SS blockssupported by a different carrier band.
 27. The terminal device accordingto claim 22, wherein Q is 3, and M is
 6. 28. The terminal deviceaccording to claim 22, wherein the one or more processors are configuredto execute the instructions to cause the terminal device to: detect thePBCH and obtain a data bits width of the PBCH; and obtain the SS blocktime index according to the data bits width of the PBCH.
 29. Theterminal device according to claim 22, wherein the DMRS of the PBCH isscrambled by a tertiary sequence (TSS).
 30. The terminal deviceaccording to claim 22, wherein the PBCH further comprises 1 bitindicating whether the (M−Q) bits need to be solved.